Tweak pointlight3d sample to work in Raster backend

- Once we add all the missing intrinsics, the locally defined ones
  can go away.
- Having the default interpreter vector width match the raster pipeline
  is a huge perf win.

Change-Id: I482e409e57791b78a0e6fb15929ae77eb0e76bf3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/265600
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed