Make runtime effect error tests simpler / more explicit

I've wanted to write a few of these lately, and (just like the shader
tests later in the file), the rigid structure was making things
difficult. It also forced some of these to be overly clever (like
commenting out main). Switch to just providing all of the SkSL for each
test case.

Change-Id: I8aff34224fa6efbdc4d67628744a9cf499eb53b5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/333796
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed