Add `out` parameters to expression and type generators.
Use the new helper classes in TextGenerator.
Cleans up bad formatting.
Prepares the writer generating 'pre' statements, required for atomics.
If-else statements are generated slightly differently. This is done so that 'pre' statements for the else conditions are scoped correctly. This is identical to the HLSL writer.
Bug tint:892
Change-Id: I4c6e96c90673ba30898b3682bf3198497d63a2d4
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/56067
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
f24b37e122