Fixed a couple of spots where sksl didn't have proper array support.

vec2 x[3] worked, but vec2[3] x didn't. Interface blocks also did
not work with array sizes.

BUG=skia:

Change-Id: I45b424891db46804f1e3c1f4793470b7b501a6de
Reviewed-on: https://skia-review.googlesource.com/8523
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
8 files changed