Revert "Revert "Convert sksl_frag.sksl to an IRIntrinsicMap""

This reverts commit 2d403f203b00fbefe4c7c63cef4b02b355467fa2.

Change-Id: Idbcf128f170d17c371221e57ef05a5dc5e306e3b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/321777
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
4 files changed