[clang] [llvm] [Clang][Darwin] Introduce `SubFrameworks` as a SDK default location (PR #115048)

[Cyndy Ishida via cfe-commits]

cyndyishida wrote:

> Do we also need to update `darwin::Linker::ConstructJob(...)`?

I thought about it, but clang already doesn't for today's default paths so I decided against it. It seems only pass extra paths to the linker for platform-specific directories like `DriverKit`. Xcode's `ld` passes its own path to `S/L/F` 

https://github.com/llvm/llvm-project/pull/115048