Implement comparison ops in RP codegen.

We now have comparison ops ==, !=, <, and <= for both int and float
types in Raster Pipeline. These use the same basic mechanism as
addition.

Change-Id: Ib7b17679178fb35f7dd3eaf98203090ffa214b1b
Bug: skia:13676
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/611045
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed