Revert "attempt 2: add experimental bilerp_clamp_8888 stage"

This reverts commit 8a64e52a98d178be13fd137b3b3a3c6aff457d85.

Reason for revert:

Test-Android-Clang-NexusPlayer-CPU-Moorefield-x86-Release-All-Android
Test-Android-Clang-NexusPlayer-GPU-PowerVR-x86-Release-All-Android

Original change's description:
> attempt 2: add experimental bilerp_clamp_8888 stage
> 
> It looks like we can specialize hot image shaders into their
> own single stages for a good speedup on both x86 and ARM.
> 
> I've started here with bilerp_clamp_8888, and will
> follow up with bgra and 565, and lowp versions of those,
> and probably also the same for nearest neighbors.
> 
> All pixels are identical in GMs.
> 
> Change-Id: Ib5ed6e528efd9e3eed96ba67d02fbec2e8133a81
> Reviewed-on: https://skia-review.googlesource.com/86860
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,liyuqian@google.com

Change-Id: I34409a7b4aee4fd54baee44f7fc53bd0982500fe
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/86601
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
7 files changed