Optimize remaining simple 1-argument intrinsics.

Aside from sqrt() and normalize(), we now optimize all the intrinsics
which take a single argument as input, and return that argument with
each of its components permuted as output.

This CL also introduces a minor restriction--we no longer optimize
intrinsics which evaluate to inf or nan, such as `inversesqrt(-1)`.
These will be left in the source as-is.

Change-Id: I4919b3c18a2df81accd6daf2f650b9f587ff43fc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/406577
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
25 files changed