Fix for loops with multiple init-variables in GLSL.

When a Block is detected in the for loop's init-statement, we now
synthesize a scope and write the init-statement directly above the for
loop and leave the for loop's init-stmt section empty.

Change-Id: I3e89c6a4328a79e49b8a19faae7975629cd0e152
Bug: skia:11860
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/396820
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2 files changed