Fix SPIR-V code generation when unreachable code exists.

This will allow us to disable dead-code elimination and run performance
tests.

Change-Id: Ia98aa88e8db511e77ad2fb669af128f4510285ae
Bug: skia:11361
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374316
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed