Revert "Add an isinf() polyfill for tessellation shaders"

This reverts commit 6904303a66737b6fde5605d53161f40590a7f2a2.

Reason for revert: I don't trust it

Original change's description:
> Add an isinf() polyfill for tessellation shaders
>
> Tessellation uses infinity to flag conics, and also as a conic weight
> that converts them into triangles. The es2 shading language doesn't
> support infinity. This CL adds a "portable infinity" mode, where we
> pretend inputs >= 2^126 are infinity. The rationale for doing this is
> that those numbers are so large, they will overflow if we try to do any
> bezier math with then anyway.
>
> Bug: chromium:1220246
> Change-Id: I3ad29ebb6fbbad5d23cfdba7a2717605009f8180
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/423697
> Commit-Queue: Chris Dalton <csmartdalton@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: chromium:1220246
Change-Id: I1e8f555b766118a49987fd4c5ea150b59b07c1e9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/427920
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
15 files changed