More SkRuntimeEffect tests

- 'in' variables can't be arrays (applies to all SkSL)
- 'in' and 'uniform' variables are restricted to a fixed
  list of types.

Change-Id: I957ce1ad33aaf6b5970ca7204c568bb533bc86d6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/261436
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
4 files changed