fixed glfw example for arm64 (#38426)

* fixed glfw example for arm64

* jenn feedback

Author: gaaclarke

examples/glfw/CMakeLists.txt

@@ -1,6 +1,7 @@
 cmake_minimum_required(VERSION 3.15)
 project(FlutterEmbedderGLFW)
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11" )
+set(FLUTTER_ENGINE_VARIANT "host_debug_unopt" CACHE STRING "")
 
 add_executable(flutter_glfw FlutterEmbedderGLFW.cc)
 
@@ -21,7 +22,7 @@ include_directories(${CMAKE_SOURCE_DIR}/../../../third_party/glfw/include)
 # This is assuming you've built a local version of the Flutter Engine.  If you
 # downloaded yours is from the internet you'll have to change this.
 include_directories(${CMAKE_SOURCE_DIR}/../../shell/platform/embedder)
-find_library(FLUTTER_LIB flutter_engine PATHS ${CMAKE_SOURCE_DIR}/../../../out/host_debug_unopt)
+find_library(FLUTTER_LIB flutter_engine PATHS ${CMAKE_SOURCE_DIR}/../../../out/${FLUTTER_ENGINE_VARIANT})
 target_link_libraries(flutter_glfw ${FLUTTER_LIB})
 
 # Copy the flutter library here since the shared library

examples/glfw/run.sh

@@ -1,14 +1,20 @@
 #!/bin/bash
 set -e # Exit if any program returns an error.
 
+if uname -m | grep "arm64"; then
+    variant="host_debug_unopt_arm64"
+else
+    variant="host_debug_unopt"
+fi
+
 #################################################################
 # Make the host C++ project.
 #################################################################
 if [ ! -d debug ]; then
     mkdir debug
 fi
 cd debug
-cmake -DCMAKE_BUILD_TYPE=Debug ..
+cmake -DCMAKE_BUILD_TYPE=Debug -DFLUTTER_ENGINE_VARIANT=$variant ..
 make
 
 #################################################################
@@ -17,11 +23,12 @@ make
 if [ ! -d myapp ]; then
     flutter create myapp
 fi
+
 cd myapp
 cp ../../main.dart lib/main.dart
 flutter build bundle \
         --local-engine-src-path ../../../../../ \
-        --local-engine=host_debug_unopt
+        --local-engine=$variant
 cd -
 
 #################################################################