Work around a Mac compiler bug with "!isinf()"

Bug: skia:12219
Change-Id: I877cece94305bcec0c36d94643f4ad17a811ae7a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/429296
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed