Move Program_GetUniformInfo into SkSL::Program.

This doesn't seem like an SkVM-specific utility.

At present it's only used by particles. Runtime effects have a
similar check, but it's done directly in
SkRuntimeEffect::MakeInternal. (Maybe this code should just move into
Particles? WDYT?)

Change-Id: Ia3e354782f4cc124fd1d89ac25f39739bc76146c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/604377
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
7 files changed