The generators were not setting `emit_continuing_` when emitting while
loops. This caused a crash when a `continue` was encountered. This CL
adds the `emit_continuing_` setup to the while emission. It also guards
the `emit_continuing_` usage with making sure the function is setup.
Bug: tint:1490
Change-Id: Ia89c49e567acda71a1f851a582103723cff71d49
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/93960
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
dan sinclair