Improve CI for libgccjit 12

Author: antoyo

.github/workflows/gcc12.yml

@@ -44,7 +44,13 @@ jobs:
 
     - name: Install packages
       # `llvm-14-tools` is needed to install the `FileCheck` binary which is used for asm tests.
-      run: sudo apt-get install ninja-build ripgrep llvm-14-tools libgccjit-12-dev
+      run: |
+        sudo apt-get install ninja-build ripgrep llvm-14-tools libgccjit-12-dev
+        gcc -v
+        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 10
+        sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc-12 10
+        gcc -v
+        cc -v
 
     - name: Setup path to libgccjit
       run: echo /usr/lib/gcc/x86_64-linux-gnu/12 > gcc_path
@@ -121,4 +127,4 @@ jobs:
         # TODO(antoyo): add --build-sysroot when the build with libgccjit 12 is fixed.
         # FIXME(antoyo): we need to set GCC_EXEC_PREFIX so that the linker can find the linker plugin.
         # Not sure why it's not found otherwise.
-        GCC_EXEC_PREFIX=/usr/lib/gcc/ ./test.sh --release --clean ${{ matrix.commands }} --no-default-features
+        ./test.sh --release --clean ${{ matrix.commands }} --no-default-features