Separate out building/testing steps

Co-authored-by:  Jim Huang <[email protected]>

.github/workflows/main.yml

@@ -9,17 +9,29 @@ jobs:
       matrix:
         compiler: [gcc, clang]
     steps:
-      - name: checkout code
+      - name: Checkout code
         uses: actions/checkout@v4
       - name: Install prerequisite
         run: |
           sudo apt-get update -q -y
           sudo apt-get install -q -y file
           sudo apt-get install -q -y build-essential
-      - name: Build artifact
+      - name: Build stage 1 artifact
         env:
           CC: ${{ matrix.compiler }}
         run: |
           make clean
-          make test-all -j || exit 1
+          make slimcc
+        shell: bash
+      - name: Test stage 1
+        run: |
+          make test || exit 1
+        shell: bash
+      - name: Build stage 2 artifact
+        run: |
+          make stage2/slimcc
+        shell: bash
+      - name: Test stage 2
+        run: |
+          make test-stage2 || exit 1
         shell: bash