Add helper function to pick an op/spvid by type.

This pattern was repeated several times in the code, so now it's a
dedicated function.

Change-Id: I31c32414aca3bc99ab655d8a480a849184a11037
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/531836
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
1 file changed