Reduce template usage in vector-coalesce functionality.

The main loop of vector-coalesce is now a single function that operates
exclusively on double values, rather than being templated on its input
types.

A similar approach should work equally well on evaluate-n-way-intrinsic.

Change-Id: Ic2848b52365ed5e38f6432f881b2ac593668a148
Bug: skia:12233
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437917
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed