There should definitely be a test that -std=c23 -pedantic-errors gives errors for these constructs (I'd say also test that -std=c23 -pedantic-errors -Wno-c23-c2y-compat doesn't diagnose them, while -std=c2y -Wc23-c2y-compat does). Not yet reviewed the rest of the patch.
-- Joseph S. Myers josmy...@redhat.com
