This is necessary for proper constant-folding, and can help us generate
better code. Most examples are pretty contrived, but a realistic benefit
can be found in inlined code (see TrivialArgumentsInlineDirectly.glsl).
Change-Id: I86aac9d48a70ae35a15109fd0b04400ae39a3b47
Bug: skia:13387
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/547277
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
