[llvm] TargetMachine: Remove pointer-size query methods (PR #226404)

[Jiaxun Yang via llvm-commits]

FlyGoat wrote:

> > Really the ABI should be fully computable from the triple alone. The ABI name is a really pervasive hack that really should have been encoded or implied directly in the triple
> 
> Somewhat related, this is one of several reasons why I want libc-less environment names in the triple:
> 
>     * [[llvm][Triple] Add libc-less variants of some environments #168042](https://github.com/llvm/llvm-project/pull/168042)
> 
>     * [[Triple] Add libc-less `x32` environment #202795](https://github.com/llvm/llvm-project/pull/202795)
> 
> 
> It would be nice if we could build some consensus on moving in the direction that the triple encodes all the necessary (and accurate) ABI information.

Maybe for barmetal it ought to be `elf` environment rather than ABI only, at least that's how GNU tools describe it.

Anyway I think that warrants a RFC for discussion at least.

https://github.com/llvm/llvm-project/pull/226404