For samplers with NaN mLodMinClamp or mLodMaxClamp, the equality
operator returned false.
Adds checks for finite values, and also early returns if two pointers
are equal.
Bug: dawn:143, chromium:965633
Change-Id: Id5998d6eec275af0fbe30e3b4fcb3eed4fe64c6a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/7401
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Idan Raiter <idanr@google.com>
