SkSL: Hide non-square (half) matrices from runtime effects

Missed these when I moved the float versions earlier. Non-square
matrices don't exist in our minimum spec (GLSL ES 1.0).

Bug: skia:11093
Change-Id: I09b3ab71199bc70d9b54302c14b93bc3f3dec2d0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/347042
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
1 file changed