Add utility for creating test-only GrProgramInfos

This is complete overkill for what these GMs require but it will help centralize things.

Change-Id: If30cbd9a9cfc8fcc1fe96fc9ca1b4cb17cdeb4bd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255824
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
6 files changed