wip: extract testing matrices for x86-linux gnu and musl

.github/workflows/ci.yml

@@ -256,6 +256,60 @@ jobs:
               ruby -rrcd_test -S rake test
             "
 
+  test_x86-linux-gnu:
+    name: x86-linux-gnu
+    needs: build_native_gem
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby: ["3.3", "3.2", "3.1", "3.0", "2.7", "2.6", "2.5", "2.4"]
+        platform: [x86-linux, x86-linux-gnu]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Download gem-${{ matrix.platform }}
+        uses: actions/download-artifact@v3
+        with:
+          name: gem-${{ matrix.platform }}
+      - name: Run tests
+        run: |
+          docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+          docker run --rm -v $PWD:/work -w /work \
+            --platform=linux/386 ruby:${{ matrix.ruby }} \
+            sh -c "
+              gem install --local *.gem --verbose &&
+              cd test/rcd_test/ &&
+              bundle install &&
+              ruby -rrcd_test -S rake test
+            "
+
+  test_x86-linux-musl:
+    name: x86-linux-musl
+    needs: build_native_gem
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby: ["3.3", "3.2", "3.1", "3.0", "2.7", "2.6", "2.5", "2.4"]
+        platform: [x86-linux-musl]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Download gem-${{ matrix.platform }}
+        uses: actions/download-artifact@v3
+        with:
+          name: gem-${{ matrix.platform }}
+      - name: Run tests
+        run: |
+          docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+          docker run --rm -v $PWD:/work -w /work \
+            --platform=linux/386 ruby:${{ matrix.ruby }}-alpine \
+            sh -c "
+              gem install --local *.gem --verbose &&
+              cd test/rcd_test/ &&
+              bundle install &&
+              ruby -rrcd_test -S rake test
+            "
+
   test_native_gem:
     name: test native
     needs: build_native_gem