Vulkan: Add debugging code for SPIRV transformer.
Vulkan: Add debugging code for SPIRV transformer.

Requires a custom define for output.

Bug: angleproject:3572
Change-Id: I3721c4067c61f3e22ce7c047054b74d3fe468d8f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2578058
Reviewed-by: Tim Van Patten <c7814369a8d3d5671c484acc7b3215f1bf4221be@google.com>
Reviewed-by: Shahbaz Youssefi <582eeec4f08a2ccd61e3ef52115e6e7c571582de@chromium.org>
Commit-Queue: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@chromium.org>

ppy/angle,ppy/angle,ppy/angle,ppy/angle