WASM: Support 64bit integers, drop PHP 7.0 and 7.1 (#74)

Enables 64bit arithmetic in all PHP.wasm builds.

In particular, this PR:

* Builds PHP with ` -D__x86_64__ ` to enable 64bit integers and links
the entire project with `-s WASM_BIGINT=1` to use the native JavaScript
BigInt for handling large integers in the JavaScript module.
* Adds the same ` -D__x86_64__ ` CLI arg to nearly all the WASM
dependencies. The only exceptions are `libwebp` and `libopenssl` where
adding that flag triggered compilation errors. We can very likely fix
them, but I didn't find a good reason to so we'll keep using 32bit ints
in two libraries until a good reason emerges.
* Drops support for PHP 7.0 and 7.1.

## Implementation

As it turns out, Emscripten and WebAssembly just support 64bit integers.
You can build this program and you'll see

```c
#include <stdio.h>
#include <stdlib.h>

int main() {
    printf("Data type sizes in this environment:\n");
    printf("Size of int: %d bytes\n", SIZEOF_INT);
    printf("Size of long: %d bytes\n", SIZEOF_LONG);
    printf("Size of long long: %d bytes\n", SIZEOF_LONG_LONG);
    printf("Size of int64_t: %zu bytes\n", sizeof(int64_t));
    return 0;
}
/**
 * Prints:
 * Size of int: 4 bytes
 * Size of long: 4 bytes
 * Size of long long: 8 bytes
 * Size of int64_t: 8 bytes
 */
```

I'm not sure when that happened. Or was it always like that? In any
case, PHP will use 64bit integers for its arithmetics and data types
when the `__x86_64__` preprocessor flag is present. This PR adds that
flag and rebuilds everything.

Unfortunately, when PHP detects `__x86_64__`, it also assumes it can
inline assembly instructions via `__asm__`. I don't believe this is
supported in Emscripten – we could make sure with the Google team. In
either case, I had to hack my way around it by setting the GLIBC macro
to 0 in specific files via different techniques.

We'll likely have to revisit and adjust this code in some way on every
major PHP release. In an ideal scenario, we would contribute a PR to PHP
core with preprocessor branches dedicated to WebAssembly builds.

### What's the net effect of this PR?

* PHP uses the `long long` data type for 64bit integers
* The JavaScript module uses BigInt class to handle large integers
* We **do not** use the memory64 spec, 64bit pointers, or 64bit address
space.

I can see two reasons to switch to the 64bit memory space:

* [Use more than 4GB of memory in the WASM
module](https://spidermonkey.dev/blog/2025/01/15/is-memory64-actually-worth-using.html).
* Potentially get a munmap()–supporting allocator and remove our custom
PHP memory allocator. We may or may not get it by building with Memory64
and I'd say it's out of scope of this PR.

Memory64 also has a downside: it [slows down the WASM program by about
10%](https://spidermonkey.dev/blog/2025/01/15/is-memory64-actually-worth-using.html):

> By reserving 4GB of memory for all 32-bit WebAssembly modules, it is
impossible to go out of bounds. The largest possible pointer value,
2^32-1, will simply land inside the reserved region of memory and trap.
This means that, when running 32-bit wasm on a 64-bit system, we can
omit all bounds checks
entirely[5](https://spidermonkey.dev/blog/2025/01/15/is-memory64-actually-worth-using.html#fn:5).
> 
> This optimization is impossible for Memory64. The size of the
WebAssembly address space is the same as the size of the host address
space. Therefore, we must pay the cost of bounds checks on every access,
and as a result, Memory64 is slower.

## Testing instructions

* Confirm all the CI tests pass. I've added a bunch of 64bit-specific
tests.

Author: adamziel

package.json

@@ -33,8 +33,6 @@
 		"recompile:php:web:jspi:7.4": "nx recompile-php:jspi php-wasm-web -- --PHP_VERSION=7.4 ",
 		"recompile:php:web:jspi:7.3": "nx recompile-php:jspi php-wasm-web -- --PHP_VERSION=7.3 ",
 		"recompile:php:web:jspi:7.2": "nx recompile-php:jspi php-wasm-web -- --PHP_VERSION=7.2 ",
-		"recompile:php:web:jspi:7.1": "nx recompile-php:jspi php-wasm-web -- --PHP_VERSION=7.1 ",
-		"recompile:php:web:jspi:7.0": "nx recompile-php:jspi php-wasm-web -- --PHP_VERSION=7.0 ",
 		"recompile:php:web:asyncify:all": "nx recompile-php:asyncify:all php-wasm-web",
 		"recompile:php:web:asyncify:8.4": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=8.4 ",
 		"recompile:php:web:asyncify:8.3": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=8.3 ",
@@ -44,8 +42,6 @@
 		"recompile:php:web:asyncify:7.4": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=7.4 ",
 		"recompile:php:web:asyncify:7.3": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=7.3 ",
 		"recompile:php:web:asyncify:7.2": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=7.2 ",
-		"recompile:php:web:asyncify:7.1": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=7.1 ",
-		"recompile:php:web:asyncify:7.0": "nx recompile-php:asyncify php-wasm-web -- --PHP_VERSION=7.0 ",
 		"recompile:php:node": "nx recompile-php:all php-wasm-node ",
 		"recompile:php:node:jspi:all": "nx recompile-php:jspi:all php-wasm-node ",
 		"recompile:php:node:jspi:8.4": "nx recompile-php:jspi php-wasm-node -- --PHP_VERSION=8.4 ",
@@ -56,8 +52,6 @@
 		"recompile:php:node:jspi:7.4": "nx recompile-php:jspi php-wasm-node -- --PHP_VERSION=7.4 ",
 		"recompile:php:node:jspi:7.3": "nx recompile-php:jspi php-wasm-node -- --PHP_VERSION=7.3 ",
 		"recompile:php:node:jspi:7.2": "nx recompile-php:jspi php-wasm-node -- --PHP_VERSION=7.2 ",
-		"recompile:php:node:jspi:7.1": "nx recompile-php:jspi php-wasm-node -- --PHP_VERSION=7.1 ",
-		"recompile:php:node:jspi:7.0": "nx recompile-php:jspi php-wasm-node -- --PHP_VERSION=7.0 ",
 		"recompile:php:node:asyncify:all": "nx recompile-php:asyncify:all php-wasm-node ",
 		"recompile:php:node:asyncify:8.4": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=8.4 ",
 		"recompile:php:node:asyncify:8.3": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=8.3 ",
@@ -66,9 +60,7 @@
 		"recompile:php:node:asyncify:8.0": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=8.0 ",
 		"recompile:php:node:asyncify:7.4": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=7.4 ",
 		"recompile:php:node:asyncify:7.3": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=7.3 ",
-		"recompile:php:node:asyncify:7.2": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=7.2 ",
-		"recompile:php:node:asyncify:7.1": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=7.1 ",
-		"recompile:php:node:asyncify:7.0": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=7.0 "
+		"recompile:php:node:asyncify:7.2": "nx recompile-php:asyncify php-wasm-node -- --PHP_VERSION=7.2 "
 	},
 	"private": true,
 	"dependencies": {

packages/php-wasm/compile/Makefile

@@ -222,14 +222,14 @@ oniguruma/jspi/dist/root/lib/lib/libonig.a: base-image
 	docker cp $$(docker create playground-php-wasm:oniguruma):/root/lib/include ./oniguruma/jspi/dist/root/lib/
 
 libcurl_asyncify: libcurl/asyncify/dist/root/lib/lib/libcurl.a
-libcurl/asyncify/dist/root/lib/lib/libcurl.a: base-image libz libopenssl
+libcurl/asyncify/dist/root/lib/lib/libcurl.a: base-image libz libopenssl_asyncify
 	mkdir -p ./libcurl/asyncify/dist/root/lib
 	docker build -f ./libcurl/Dockerfile -t playground-php-wasm:libcurl . --progress=plain
 	docker cp $$(docker create playground-php-wasm:libcurl):/root/curl-7.69.1/lib/.libs ./libcurl/asyncify/dist/root/lib/lib
 	docker cp $$(docker create playground-php-wasm:libcurl):/root/curl-7.69.1/include/ ./libcurl/asyncify/dist/root/lib
 
 libcurl_jspi: libcurl/jspi/dist/root/lib/lib/libcurl.a
-libcurl/jspi/dist/root/lib/lib/libcurl.a: base-image libz libopenssl
+libcurl/jspi/dist/root/lib/lib/libcurl.a: base-image libz libopenssl_jspi
 	mkdir -p ./libcurl/jspi/dist/root/lib
 	docker build -f ./libcurl/Dockerfile -t playground-php-wasm:libcurl . --progress=plain --build-arg JSPI=1
 	docker cp $$(docker create playground-php-wasm:libcurl):/root/curl-7.69.1/lib/.libs ./libcurl/jspi/dist/root/lib/lib

packages/php-wasm/compile/base-image/Dockerfile

@@ -79,7 +79,7 @@ RUN chmod a+x /root/replace-across-lines.sh
 # * Enables adding -sSIDE_MODULE when running emcc
 #
 # Usage:
-#  EMCC_SKIP="-lz -lxml2" EMCC_FLAGS="-sSIDE_MODULE" emmake make
+#  EMCC_SKIP="-lz -lxml2" EMCC_FLAGS=" -D__x86_64__ -sSIDE_MODULE" emmake make
 #               ↑                            ↑
 #    ┌──────────┴─────────────┐   ┌──────────┴─────────────┐
 #    │  skip those flags when │   │  add these flags when  │

packages/php-wasm/compile/bison2.7/dist/usr/local/bison/bin/bison

@@ -59,7 +59,7 @@ RUN CPPFLAGS="-I/root/lib/include " \
 RUN if [ "$JSPI" = "1" ]; then \
     source /root/emsdk/emsdk_env.sh && \
     EMCC_SKIP="-lc -lz -lcurl -lssl " \
-    EMCC_FLAGS="-sSIDE_MODULE -Wl,--wrap=select -sSUPPORT_LONGJMP=wasm -fwasm-exceptions " emmake make || true; \
+    EMCC_FLAGS=" -D__x86_64__ -sSIDE_MODULE -Wl,--wrap=select -sSUPPORT_LONGJMP=wasm -fwasm-exceptions " emmake make || true; \
 fi
 
 RUN if [ "$JSPI" != "1" ]; then \
@@ -77,11 +77,11 @@ fi
 RUN if [ "$JSPI" != "1" ]; then \
     source /root/emsdk/emsdk_env.sh && \
     EMCC_SKIP="-lc -lz -lcurl -lssl " \
-    EMCC_FLAGS="-sSIDE_MODULE -Wl,--wrap=select " emmake make -i || true; \
+    EMCC_FLAGS=" -D__x86_64__ -sSIDE_MODULE -Wl,--wrap=select " emmake make -i || true; \
 fi
 
 RUN if [ "$JSPI" != "1" ]; then \
     source /root/emsdk/emsdk_env.sh && \
     EMCC_SKIP="-lc -lz -lcurl -lssl " \
-    EMCC_FLAGS="-sSIDE_MODULE -Wl,--wrap=select " emmake make install -i || true; \
+    EMCC_FLAGS=" -D__x86_64__ -sSIDE_MODULE -Wl,--wrap=select " emmake make install -i || true; \
 fi

packages/php-wasm/compile/bison2.7/dist/usr/local/bison/lib/liby.a

@@ -0,0 +1 @@
+../libcurl.la

packages/php-wasm/compile/libcurl/Dockerfile

@@ -0,0 +1,41 @@
+# libcurl.la - a libtool library file
+# Generated by libtool (GNU libtool) 2.4.6 Debian-2.4.6-13
+#
+# Please DO NOT delete this file!
+# It is necessary for linking the library.
+
+# The name that we can dlopen(3).
+dlname=''
+
+# Names of this library.
+library_names=''
+
+# The name of the static archive.
+old_library='libcurl.a'
+
+# Linker flags that cannot go in dependency_libs.
+inherited_linker_flags=''
+
+# Libraries that this one depends upon.
+dependency_libs=' -L/root/lib/lib -lssl -lcrypto -lz'
+
+# Names of additional weak libraries provided by this library
+weak_library_names=''
+
+# Version information for libcurl.
+current=10
+age=6
+revision=0
+
+# Is this an already installed library?
+installed=yes
+
+# Should we warn about portability when linking against -modules?
+shouldnotlink=no
+
+# Files to dlopen/dlpreopen
+dlopen=''
+dlpreopen=''
+
+# Directory that this library needs to be installed in:
+libdir='/root/lib/lib'

packages/php-wasm/compile/libcurl/asyncify/dist/root/lib/lib/.libs/libcurl.a

@@ -25,6 +25,6 @@ RUN cd libedit-20221030-3.1 && \
 # http://lists.busybox.net/pipermail/buildroot/2016-January/149100.html
 RUN cd libedit-20221030-3.1 && \
     source /root/emsdk/emsdk_env.sh && \
-    EMCC_SKIP="-lc -lncurses " EMCC_FLAGS=" -sSIDE_MODULE -D__STDC_ISO_10646__=201103L " \
+    EMCC_SKIP="-lc -lncurses " EMCC_FLAGS=" -D__x86_64__  -sSIDE_MODULE -D__STDC_ISO_10646__=201103L " \
     emmake make && \
     emmake make install

packages/php-wasm/compile/libcurl/asyncify/dist/root/lib/lib/.libs/libcurl.la

@@ -32,7 +32,7 @@ RUN set -euxo pipefail; \
 RUN set -euxo pipefail; \
 	source /root/emsdk/emsdk_env.sh; \
 	export JSPI_FLAGS=$(if [ "$JSPI" = "1" ]; then echo "-sSUPPORT_LONGJMP=wasm -fwasm-exceptions"; else echo ""; fi) && \
-	EMCC_FLAGS="-fPIC $JSPI_FLAGS" emmake make; \
+	EMCC_FLAGS=" -D__x86_64__ -fPIC $JSPI_FLAGS" emmake make; \
 	emmake make install;
 
 RUN ls -R /root/install

packages/php-wasm/compile/libcurl/asyncify/dist/root/lib/lib/.libs/libcurl.lai

@@ -21,10 +21,10 @@ RUN     source /root/emsdk/emsdk_env.sh && \
         emcmake cmake -G"Unix Makefiles" -DCMAKE_INSTALL_DEFAULT_PREFIX=/root/lib
 RUN source /root/emsdk/emsdk_env.sh && \
     export JSPI_FLAGS=$(if [ "$JSPI" = "1" ]; then echo "-sSUPPORT_LONGJMP=wasm -fwasm-exceptions"; else echo ""; fi) && \
-    EMCC_SKIP="-lc -lz" EMCC_FLAGS="-sSIDE_MODULE $JSPI_FLAGS" emmake make
+    EMCC_SKIP="-lc -lz" EMCC_FLAGS=" -D__x86_64__ -sSIDE_MODULE $JSPI_FLAGS" emmake make
 RUN source /root/emsdk/emsdk_env.sh && \
     export JSPI_FLAGS=$(if [ "$JSPI" = "1" ]; then echo "-sSUPPORT_LONGJMP=wasm -fwasm-exceptions"; else echo ""; fi) && \
-    EMCC_FLAGS="$JSPI_FLAGS" emmake make install
+    EMCC_FLAGS=" -D__x86_64__ $JSPI_FLAGS" emmake make install
 RUN sed -i 's/lib32/lib/g' /root/lib/lib32/pkgconfig/libjpeg.pc
 # @TODO: Do not remove dependencies like this – it's too easy to miss something.
 #        Instead, source them from another directory and end up with a clean build.

packages/php-wasm/compile/libcurl/jspi/dist/root/lib/lib/.libs/libcurl.a

@@ -0,0 +1,28 @@
+
+####### Expanded from @PACKAGE_INIT@ by configure_package_config_file() #######
+####### Any changes to this file will be overwritten by the next CMake run ####
+####### The input file was Config.cmake.in                            ########
+
+get_filename_component(PACKAGE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)
+
+macro(set_and_check _var _file)
+  set(${_var} "${_file}")
+  if(NOT EXISTS "${_file}")
+    message(FATAL_ERROR "File or directory ${_file} referenced by variable ${_var} does not exist !")
+  endif()
+endmacro()
+
+macro(check_required_components _NAME)
+  foreach(comp ${${_NAME}_FIND_COMPONENTS})
+    if(NOT ${_NAME}_${comp}_FOUND)
+      if(${_NAME}_FIND_REQUIRED_${comp})
+        set(${_NAME}_FOUND FALSE)
+      endif()
+    endif()
+  endforeach()
+endmacro()
+
+####################################################################################
+
+include("${CMAKE_CURRENT_LIST_DIR}/libjpeg-turboTargets.cmake")
+check_required_components("libjpeg-turbo")

packages/php-wasm/compile/libedit/Dockerfile

@@ -0,0 +1,43 @@
+# This is a basic version file for the Config-mode of find_package().
+# It is used by write_basic_package_version_file() as input file for configure_file()
+# to create a version-file which can be installed along a config.cmake file.
+#
+# The created file sets PACKAGE_VERSION_EXACT if the current version string and
+# the requested version string are exactly the same and it sets
+# PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version.
+# The variable CVF_VERSION must be set before calling configure_file().
+
+set(PACKAGE_VERSION "3.0.3")
+
+if (PACKAGE_FIND_VERSION_RANGE)
+  # Package version must be in the requested version range
+  if ((PACKAGE_FIND_VERSION_RANGE_MIN STREQUAL "INCLUDE" AND PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION_MIN)
+      OR ((PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "INCLUDE" AND PACKAGE_VERSION VERSION_GREATER PACKAGE_FIND_VERSION_MAX)
+        OR (PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "EXCLUDE" AND PACKAGE_VERSION VERSION_GREATER_EQUAL PACKAGE_FIND_VERSION_MAX)))
+    set(PACKAGE_VERSION_COMPATIBLE FALSE)
+  else()
+    set(PACKAGE_VERSION_COMPATIBLE TRUE)
+  endif()
+else()
+  if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
+    set(PACKAGE_VERSION_COMPATIBLE FALSE)
+  else()
+    set(PACKAGE_VERSION_COMPATIBLE TRUE)
+    if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
+      set(PACKAGE_VERSION_EXACT TRUE)
+    endif()
+  endif()
+endif()
+
+
+# if the installed or the using project don't have CMAKE_SIZEOF_VOID_P set, ignore it:
+if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "" OR "4" STREQUAL "")
+  return()
+endif()
+
+# check that the installed version has the same 32/64bit-ness as the one which is currently searching:
+if(NOT CMAKE_SIZEOF_VOID_P STREQUAL "4")
+  math(EXPR installedBits "4 * 8")
+  set(PACKAGE_VERSION "${PACKAGE_VERSION} (${installedBits}bit)")
+  set(PACKAGE_VERSION_UNSUITABLE TRUE)
+endif()

packages/php-wasm/compile/libiconv/Dockerfile

@@ -0,0 +1,49 @@
+#----------------------------------------------------------------
+# Generated CMake target import file for configuration "Release".
+#----------------------------------------------------------------
+
+# Commands may need to know the format version.
+set(CMAKE_IMPORT_FILE_VERSION 1)
+
+# Import target "libjpeg-turbo::jpeg" for configuration "Release"
+set_property(TARGET libjpeg-turbo::jpeg APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE)
+set_target_properties(libjpeg-turbo::jpeg PROPERTIES
+  IMPORTED_LINK_INTERFACE_LANGUAGES_RELEASE "C"
+  IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/lib32/libjpeg.a"
+  )
+
+list(APPEND _cmake_import_check_targets libjpeg-turbo::jpeg )
+list(APPEND _cmake_import_check_files_for_libjpeg-turbo::jpeg "${_IMPORT_PREFIX}/lib32/libjpeg.a" )
+
+# Import target "libjpeg-turbo::turbojpeg" for configuration "Release"
+set_property(TARGET libjpeg-turbo::turbojpeg APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE)
+set_target_properties(libjpeg-turbo::turbojpeg PROPERTIES
+  IMPORTED_LINK_INTERFACE_LANGUAGES_RELEASE "C"
+  IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/lib32/libturbojpeg.a"
+  )
+
+list(APPEND _cmake_import_check_targets libjpeg-turbo::turbojpeg )
+list(APPEND _cmake_import_check_files_for_libjpeg-turbo::turbojpeg "${_IMPORT_PREFIX}/lib32/libturbojpeg.a" )
+
+# Import target "libjpeg-turbo::turbojpeg-static" for configuration "Release"
+set_property(TARGET libjpeg-turbo::turbojpeg-static APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE)
+set_target_properties(libjpeg-turbo::turbojpeg-static PROPERTIES
+  IMPORTED_LINK_INTERFACE_LANGUAGES_RELEASE "C"
+  IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/lib32/libturbojpeg.a"
+  )
+
+list(APPEND _cmake_import_check_targets libjpeg-turbo::turbojpeg-static )
+list(APPEND _cmake_import_check_files_for_libjpeg-turbo::turbojpeg-static "${_IMPORT_PREFIX}/lib32/libturbojpeg.a" )
+
+# Import target "libjpeg-turbo::jpeg-static" for configuration "Release"
+set_property(TARGET libjpeg-turbo::jpeg-static APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE)
+set_target_properties(libjpeg-turbo::jpeg-static PROPERTIES
+  IMPORTED_LINK_INTERFACE_LANGUAGES_RELEASE "C"
+  IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/lib32/libjpeg.a"
+  )
+
+list(APPEND _cmake_import_check_targets libjpeg-turbo::jpeg-static )
+list(APPEND _cmake_import_check_files_for_libjpeg-turbo::jpeg-static "${_IMPORT_PREFIX}/lib32/libjpeg.a" )
+
+# Commands beyond this point should not need to know the version.
+set(CMAKE_IMPORT_FILE_VERSION)