We had constant-folding tests for vector-scalar arithmetic, but didn't
have an equivalent SkSL unit test for vector-scalar arithmetic that
actually needs to be computed at runtime.
This exposes two SPIR-V bugs: one was previously known, but the other
is a new discovery.
Change-Id: I28737128f20b445797c6c29872335d05f94cc95c
Bug: skia:11267, skia:11788
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388739
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
