cmake+ci: fix+test sdl2-config + sdl2.pc for all supported platforms

.github/workflows/main.yml

@@ -189,6 +189,16 @@ jobs:
           -DCMAKE_BUILD_TYPE=Release \
           -DCMAKE_PREFIX_PATH=${{ env.SDL2_DIR }}
         cmake --build cmake_config_build --verbose
+    - name: Verify sdl2-config
+      run: |
+        export CC=${{ matrix.platform.cc || 'gcc' }}
+        export PATH=${{ env.SDL2_DIR }}/bin:$PATH
+        cmake/test/test_sdlconfig.sh
+    - name: Verify sdl2.pc
+      run: |
+        export CC=${{ matrix.platform.cc || 'gcc' }}
+        export PKG_CONFIG_PATH=${{ env.SDL2_DIR }}/lib/pkgconfig
+        cmake/test/test_pkgconfig.sh
     - name: Distcheck (Autotools)
       if: matrix.platform.autotools
       run: |