Add support for intrinsic radians()/degrees() in RP codegen.

These are just multiplications against a constant, so it's about as
simple as an intrinsic can get.

Change-Id: If5f90d477064928f0cff39259f1ae4265b95dee8
Bug: skia:13676
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/632516
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Arman Uguray <armansito@google.com>
14 files changed