Add GS Invocations caps to SkSL StandaloneShaderCaps

Bug: skia:
Change-Id: I58f0caf97048e62a11cf8732acc79e3c2fbc683b
Reviewed-on: https://skia-review.googlesource.com/56801
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
1 file changed