Update CI to run both old and new backends

.github/workflows/ci.yml

@@ -11,7 +11,9 @@ jobs:
       - name: build odin
         run: make release
       - name: Odin run
-        run: ./odin run examples/demo/demo.odin
+        run: |
+          ./odin run examples/demo/demo.odin
+          ./odin run examples/demo/demo.odin -llvm-api
       - name: Odin check
         run: ./odin check examples/demo/demo.odin -vet
   build_macOS:
@@ -27,7 +29,9 @@ jobs:
       - name: build odin
         run: make release
       - name: Odin run
-        run: ./odin run examples/demo/demo.odin
+        run: |
+          ./odin run examples/demo/demo.odin
+          ./odin run examples/demo/demo.odin -llvm-api
       - name: Odin check
         run: ./odin check examples/demo/demo.odin -vet
   build_windows: