[clang] [Clang] Make `-Xarch_` handling generic for all toolchains (PR #125421)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> > Right now if someone passes -Xarch_foo --offload-arch=gfx1030 and foo doesn't match it's not passed and it will print something like this. I figured that's good enough.
> 
> This part SGTM, too.
> 
> However, I don't think I've seen the answer what happens when we do pass --offload arch to cc1.
> 
> E.g. a user may accidentally paste an argument in the wrong place and instead of intended `--offload-arch=sm_52 --offload-arch=sm_80 -Xarch_sm52 --some-option-for_sm52` passes `--offload-arch=sm_52 -Xarch_sm52 --offload-arch=sm_80 --some-option-for_sm52` ?

`--offload-arch=` isn't an accepted `-cc1` argument so it won't be forwarded at all.

https://github.com/llvm/llvm-project/pull/125421