[clang] clang: Add BoundArch argument to addClangTargetOptions (PR #196504)

[Matt Arsenault via cfe-commits]

arsenm wrote:

> 
> The target-id itself was a huge mistake, I would've rejected it if it were proposed today.

Another partial solution would be to have TranslateArgs rewrite -mcpu into -mcpu + -m flags for the field, but I figured it would be confusing to have that change midstream (and still has the inconvenience of re-parsing)

> I didn't remember that we used the OffloadKind in these methods, that also seems a bit strange as I would've figured that would be implicit in the JobAction, but we don't have access to that here?

Most of these toolchain arguments take OffloadKind + BoundArch and don't know the job 


https://github.com/llvm/llvm-project/pull/196504