ci: split test build from matrix

Allow test suite to run if, for example, the C++20 builds are failing but C++11 are fine.

.github/workflows/test-build.yml

@@ -23,8 +23,8 @@ jobs:
           # only run on push *or* pull_request, not both
           concurrent_skipping: 'same_content_newer'
 
-  build-yosys:
-    name: Build Yosys
+  test-builds:
+    name: Compiler testing
     runs-on: ${{ matrix.os }}
     needs: pre_job
     if: needs.pre_job.outputs.should_skip != 'true'
@@ -48,11 +48,6 @@ jobs:
           # Add os_name
           - os: ubuntu-20.04
             os_name: focal
-          # Build for testing
-          - os: ubuntu-20.04
-            os_name: focal
-            compiler: 'clang'
-            cpp_std: 'c++11'
           # macOS build
           - os: macos-13
             compiler: 'clang'
@@ -131,7 +126,71 @@ jobs:
         with:
          submodules: true
 
-      - name: Build yosys out-of-tree
+      - name: Build
+        shell: bash
+        run: |
+          make config-${CC%%-*}
+          make -j$procs CXXSTD=$CXXSTD CC=$CC CXX=$CXX LD=$CC
+
+  build-yosys:
+    name: Reusable Yosys build
+    runs-on: ${{ matrix.os }}
+    env:
+      CC: ${{ matrix.compiler }}
+      CXX: ${{ matrix.compiler }}
+      CXXSTD: ${{ matrix.cpp_std }}
+    strategy:
+      matrix:
+        os:
+          - ubuntu-20.04
+        compiler:
+          - 'clang'
+        cpp_std:
+          - 'c++11'
+        include:
+          # Add os_name
+          - os: ubuntu-20.04
+            os_name: focal
+      fail-fast: false
+    steps:
+      - name: Install Linux Dependencies
+        if: runner.os == 'Linux'
+        shell: bash
+        run: |
+          sudo apt-get update
+          sudo apt-get install gperf build-essential bison flex libreadline-dev gawk tcl-dev libffi-dev git graphviz xdot pkg-config python python3 libboost-system-dev libboost-python-dev libboost-filesystem-dev zlib1g-dev
+
+      - name: Install macOS Dependencies
+        if: runner.os == 'macOS'
+        run: |
+          brew install bison flex gawk libffi pkg-config bash
+
+      - name: Linux runtime environment
+        if: runner.os == 'Linux'
+        shell: bash
+        run: |
+          echo "${{ github.workspace }}/.local/bin" >> $GITHUB_PATH
+          echo "procs=$(nproc)" >> $GITHUB_ENV
+
+      - name: macOS runtime environment
+        if: runner.os == 'macOS'
+        shell: bash
+        run: |
+          echo "${{ github.workspace }}/.local/bin" >> $GITHUB_PATH
+          echo "$(brew --prefix bison)/bin" >> $GITHUB_PATH
+          echo "$(brew --prefix flex)/bin" >> $GITHUB_PATH
+          echo "procs=$(sysctl -n hw.ncpu)" >> $GITHUB_ENV
+
+      - name: Tool versions
+        shell: bash
+        run: |
+          $CC --version
+          $CXX --version
+
+      - name: Checkout Yosys
+        uses: actions/checkout@v4
+
+      - name: Build
         shell: bash
         run: |
           mkdir build