Add incompleteShortIntPrecision to SkSL StandaloneShaderCaps

TBR=ethannicholas@google.com

Bug: skia:
Change-Id: If3b86e414d74072dd3e38a5507bbcbcecc3946f6
Reviewed-on: https://skia-review.googlesource.com/114378
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed