[clang] [clang] Enhance handling of Apple-specific '-arch'/'-target' option values (PR #72821)

[Fangrui Song via cfe-commits]

MaskRay wrote:

`-arch ` is also related to universal binary that many other targets don't support (and they likely don't endorse such an approach). For ELF we should definitely encourage `--target=` for cross compilation. (`-target ` has been deprecated since Clang 3.2). Picking a default version for macOS is quite odd as well.

I think we should reject `-arch ` like many other target-specific options. 
https://maskray.me/blog/2023-08-25-clang-wunused-command-line-argument

Created https://github.com/llvm/llvm-project/pull/74365

https://github.com/llvm/llvm-project/pull/72821