Reland "remove unused functions in sksl.inc"

This is a reland of 76ba2fb0a60a86606d278e7352c8915fb1992f1d

Original change's description:
> remove unused functions in sksl.inc
> 
> Bug: skia:
> Change-Id: I8f791324bbde13d51c7be2b85ee5d5fadb938e5e
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215423
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Commit-Queue: Mike Klein <mtklein@google.com>
> Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>

Bug: skia:
Change-Id: Iae5bd25db46796e8075b987a17f99f4a14513773
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215601
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
1 file changed