[Windows] Enable macros in Windows

After FetchContent changes, macros in Windows were disabled.

(cherry picked from commit 8159f5e)

Author: rintaro

CMakeLists.txt

@@ -1336,8 +1336,9 @@ if(SWIFT_INCLUDE_TOOLS)
       set(SWIFT_HOST_LIBRARIES_RPATH "$ORIGIN;$ORIGIN/../${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}")
     endif()
 
+    file(TO_CMAKE_PATH "${SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE}" swift_syntax_path)
     FetchContent_Declare(SwiftSyntax
-      SOURCE_DIR "${SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE}"
+      SOURCE_DIR "${swift_syntax_path}"
     )
     FetchContent_MakeAvailable(SwiftSyntax)
   endfunction()

utils/build-windows-toolchain.bat

@@ -252,6 +252,7 @@ cmake ^
   -D SWIFT_ENABLE_EXPERIMENTAL_DIFFERENTIABLE_PROGRAMMING=YES ^
   -D SWIFT_ENABLE_EXPERIMENTAL_STRING_PROCESSING=YES ^
   -D SWIFT_ENABLE_EXPERIMENTAL_OBSERVATION=YES ^
+  -D SWIFT_BUILD_SWIFT_SYNTAX=YES ^
 
   -D LLVM_EXTERNAL_SWIFT_SOURCE_DIR="%SourceRoot%\swift" ^
   -D LLVM_EXTERNAL_CMARK_SOURCE_DIR="%SourceRoot%\cmark" ^

utils/build-windows.bat

@@ -274,6 +274,7 @@ cmake^
     -DCMAKE_EXE_LINKER_FLAGS:STRING=/INCREMENTAL:NO^
     -DCMAKE_SHARED_LINKER_FLAGS:STRING=/INCREMENTAL:NO^
     -DSWIFT_LIT_ARGS="--time-tests"^
+    -DSWIFT_BUILD_SWIFT_SYNTAX=YES ^
     -DSWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE:PATH=%source_root%\swift-syntax^
     -S "%source_root%\swift" %exitOnError%
 
@@ -318,6 +319,7 @@ cmake^
     -DLLDB_DISABLE_PYTHON=YES^
     -DLLDB_INCLUDE_TESTS:BOOL=NO^
     -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON^
+    -DSWIFT_BUILD_SWIFT_SYNTAX=YES ^
     -S "%source_root%\llvm-project\lldb" %exitOnError%
 
 cmake --build "%build_root%\lldb" %exitOnError%