Revert of Reduced skslc memory consumption (patchset #3 id:50001 of https://codereview.chromium.org/2442063002/ )

Reason for revert:
texelFetch removed, but is used in some shaders.

Original issue's description:
> Reduced skslc memory consumption
>
> The big change here is smarter generic type handling which allows us to
> keep far fewer entries in the core symboltable. This also comments out
> a number of OpenGL builtin functions which Skia does not use and is
> unlikely to in the future.
> BUG=655673
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2442063002
>
> Committed: https://skia.googlesource.com/skia/+/cffaa70896fa5bc6c7bf98abbaafb1a755b49762

TBR=reed@google.com,ethannicholas@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=655673

Review-Url: https://codereview.chromium.org/2458723002
9 files changed