Revert "Add ES3 intrinsics isinf/isnan to public SkSL ES3."

This reverts commit e43714f490ecab72bd1dca73f296a37fc99ef415.

Reason for revert: Several Pixel (Adreno) devices failing the test

Original change's description:
> Add ES3 intrinsics isinf/isnan to public SkSL ES3.
>
> The ES3 spec doesn't mandate that `isnan` actually has to do anything,
> so the Isnan test is not enabled. (It doesn't work on my personal
> machine unless I make the NaN detectable at compile-time.)
>
> We do not support these functions in constant-expressions, as we
> currently avoid optimizing anything into a non-finite value; we leave
> expressions alone if we calculate a NaN/inf result for their value.
>
> Change-Id: Ibfdfb47b6e6134165c8780db570de04a916d2bfa
> Bug: skia:12022
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/441581
> Auto-Submit: John Stiles <johnstiles@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: John Stiles <johnstiles@google.com>

TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com,skcq-be@skia-corp.google.com.iam.gserviceaccount.com

Change-Id: I89899ed391aa870350d0452bab4a0fb75bd7be38
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:12022
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/441716
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
11 files changed