spirv-cross standalone: interface to add_hlsl_resource_binding

For Spirv to HLSL using the library I can manually assign registers using "compiler.add_hlsl_resource_binding": in particular I can force a specific register for push constants.

As far as I can tell this is not possible with "spirv-cross" standalone executable.

Am I missing something and this feature already exists? If not, I could give it a try and implement it myself, is there any interest for that?

Start by checking whether the standalone executable already exposes the behavior provided by compiler.add_hlsl_resource_binding, focusing on push-constant register assignment. Trace the standalone command interface and compare it with the library interface; the work is complete when users can request an equivalent HLSL resource binding from the executable and the resulting register assignment is verified.

Written by the indexing model from the issue text.