Script would erroneously generate for files in excluded paths because of
slash differences.
Also make the output display the path to the MSL and HLSL executable
being used.
Change-Id: I0bf55dd461c96b7b910f7a9aa9756ab2006c2a33
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/68821
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>