Clean up D3D12 shader compilation

Adds in printing of shaders and better matches other backends.

Change-Id: Ie2d7bed201e3d0a8d76262ee454632ec46b7e0aa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/397137
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed