[llvm] [ms] [llvm-ml] Add support for `@CatStr` built-in function symbol (PR #130781)

[Eric Astor via llvm-commits]

ericastor wrote:

@MisterDA:
> With this patch applied, the following macro crashes the assembler:
> 
> ...

This is absolutely correct - but turns out to be an existing issue with our handling of macro parameters in macro calls, which you can see if you use a "custom" CatStr implementation before this change goes in. I'm going to delay fixing this into a followup PR, if that's alright.

https://github.com/llvm/llvm-project/pull/130781