Check in CI if generated Fizz runtime is in sync

The generated Fizz runtime is checked into source. In CI, we'll ensure
it stays in sync by running the script and confirming nothing changed.

.circleci/config.yml

@@ -367,6 +367,19 @@ jobs:
           command: |
             yarn extract-errors
             git diff --quiet || (echo "Found unminified errors. Either update the error codes map or disable error minification for the affected build, if appropriate." && false)
+  
+  check_generated_fizz_runtime:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace: *attach_workspace
+      - *restore_node_modules
+      - run:
+          name: Confirm generated inline Fizz runtime is up to date
+          command: |
+            yarn generate-inline-fizz-runtime
+            git diff --quiet || (echo "There was a change to the Fizz runtime. Run `yarn generate-inline-fizz-runtime` and check in the result." && false)
 
   yarn_test:
     docker: *docker
@@ -494,6 +507,9 @@ workflows:
       - sync_reconciler_forks:
           requires:
             - setup
+      - check_generated_fizz_runtime:
+          requires:
+            - setup    
       - yarn_lint:
           requires:
             - setup