Replace GrClampFragmentProcessor with runtime FPs

Change-Id: Ie271fba0fa26165baac9246eaf1c729df2c7b05a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/419476
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
11 files changed