SPIR-V comma operator support

Bug: skia:
Change-Id: I9792674c49a0243017bb5f2b3c11d0678e62138e
Reviewed-on: https://skia-review.googlesource.com/21367
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
1 file changed