SPIR-V optimization diagnostics (shader-slang#1989)

* #include an absolute path didn't work - because paths were taken to always be relative.

* WIP fixing glslang error reporting.

* SPIR-V opt diagnostics.

* Small formatting tidy up.

* Disable nv-ray-tracing-motion-blur.slang for now, until merged and can rebuild slang-glslang.

* Formatting improvements.

* Some small improvements around optimizing in glslang.

* Make clear if calling optimize with 'non' in glslang no work is done (such as a pointless copy).

* Small formatting change - mainly to kick off a build.

* Upgrade slang-binaries to fix git fetch issue on TC.

* Small formatting edits. Kick build.

Author: jsmall-zzz