Inline the `continuing` block in the places where `continue` is called.
Simplifies the emission, and fixes emission of `let` statements in the loop.
This fix matches the same approach in writer/hlsl.
See: https://dawn-review.googlesource.com/c/tint/+/51784
Fixed: tint:833
Fixed: tint:914
Change-Id: If4d8cde62dfaf8efa24272854ca7ff5edc0a8234
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/55341
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
663271dca4