Revert of SkSL performance improvements (patchset #6 id:140001 of https://codereview.chromium.org/2131223002/ )

Reason for revert:
Valgrind bot failures

https://build.chromium.org/p/client.skia/builders/Test-Ubuntu-GCC-ShuttleA-GPU-GTX550Ti-x86_64-Release-Valgrind/builds/1224/steps/test_skia%20on%20Ubuntu/logs/stdio

Original issue's description:
> SkSL performance improvements (plus a couple of minor warning fixes)
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2131223002
>
> Committed: https://skia.googlesource.com/skia/+/9fd67a1f53809f5eff1210dd107241b450c48acc

TBR=benjaminwagner@google.com,egdaniel@google.com,ethannicholas@google.com
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review-Url: https://codereview.chromium.org/2143323003
34 files changed