Handle kMatrixMultiply in ByteCode -> SkVM

Raster backend now draws the bump-mapped cube sample!

Change-Id: I4ad74c50a329dcd0c9b56f2a18b1e32fd5c5eccd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/297815
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
2 files changed