Convert several SkSL->GLSL unit tests to golden outputs.

The new test files are intended to be identical to the unit tests in
every meaningful way. (Comments and formatting are not preserved
exactly.) In cases where a unit-test method contained more than one
test, multiple test files were created; in these cases, new names were
invented to match the apparent intent of each invocation.

Followup CLs will continue to migrate additional tests.

Change-Id: I785c6761ba7ee2b25b5ddc0108321734be23b77c
Bug: skia:10694
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/316678
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
91 files changed