Use the IntrinsicKind to look up SPIR-V intrinsic calls.

This is more efficient than looking up the intrinsic by name.

Change-Id: I69bc5734073477d4359ef2b37c4b37dffc90fed5
Bug: skia:11961
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405278
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
3 files changed