Update cmake-linux-x86.yml

Author: sam-astro

.github/workflows/cmake-linux-x86.yml

@@ -25,11 +25,19 @@ jobs:
 
     - name: Setup LLVM
       uses: ZhongRuoyu/setup-llvm@5bee61a33dd6160cb4dd652cd80d56ff3654535f
+
+    - name: Set up GCC
+      uses: egor-tensin/setup-gcc@v1
+      with:
+        version: latest
+        platform: x64
 
     - name: Configure CMake
       # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
       # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
       run: |
+        export CC=/usr/local/bin/gcc
+        export CXX=/usr/local/bin/g++
         mkdir ${{github.workspace}}/build
         cd ${{github.workspace}}/build
         cmake -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DLLVM_TARGETS_TO_BUILD="X86" -G Ninja ../src