SkVx: Go back to memcpy, rather than sk_unaligned_store

This was producing slightly worse code (in memsetT).

Bug: chromium:1450806
Change-Id: I3914cdb738f94907380c7e400a5dab1744b86083
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/706537
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed