Reland "Add support for matrix == and != in Metal shaders."

This reverts commit 4908a24d4b24ad34a3dce693d931654b872bff08.

Reason for revert: test fails on Adreno 5xx/6xx, will land tests
separately and disable on Adreno

Original change's description:
> Revert "Add support for matrix == and != in Metal shaders."
>
> This reverts commit c50185718830a6220b28be885cebd3959a0f0698.
>
> Reason for revert: breaking many bots
>
> Original change's description:
> > Add support for matrix == and != in Metal shaders.
> >
> > We need to polyfill an operator== and != when these are first
> > encountered in the code.
> >
> > Change-Id: I539c838ee1871bcb0c4b66abb8a4a0f91146cd4f
> > Bug: skia:11306
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/368496
> > Auto-Submit: John Stiles <johnstiles@google.com>
> > Reviewed-by: Brian Osman <brianosman@google.com>
>
> TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
>
> Change-Id: Id583109a0d167c2c58a57644b14cd5f49d670737
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: skia:11306
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/368801
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,brianosman@google.com,ethannicholas@google.com,johnstiles@google.com

Bug: skia:11306
Change-Id: If7c628b8c7a2ce40d6c88599a7660ff91c4ac67a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/368804
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
4 files changed