Inline the `continuing` block in the places where `continue` is called.
Simplifies the emission, and fixes emission of `let` statements in the loop.
Also fix random indenting of intrinsic functions.
Fixed: tint:744
Fixed: tint:818
Change-Id: I06994dbc724bc646e0435a1035b00760eaf5f5ab
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/51784
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
ada560b289