[clang] [clang][CodeGen] Make `UnqualPtrTy` truly unqualified (PR #94388)

[Jessica Clarke via cfe-commits]

jrtc27 wrote:

I think the point is there are two things going on here that people think of as unqualified:
1. "Give me a pointer that's whatever `void *` is"
2. "Give me a pointer in some address space just so I can put a global in some metadata"
The vast majority of the time we're talking about 1, which is what most people would think of unqualified as meaning. #93601 / #93914 are about the three special cases that are case 2 above. But those are a special case, and normally when people say unqualified they mean "default" address space / `void *`.

https://github.com/llvm/llvm-project/pull/94388