[llvm] [clang] [NFC] Remove Type::getInt8PtrTy (PR #71029)

[Nikita Popov via cfe-commits]

nikic wrote:

> Also adds AS = 0 as an optional argument to get() methods.

I believe that was intentionally omitted to make sure address spaces aren't forgotten (getUnqual is used for the case where they aren't relevant). cc @arsenm 

Not sure whether this consideration is still relevant with opaque pointers, where we no longer create random pointer types for bitcasts all over the place. It may be better to accept the 0 default for simplicity.

https://github.com/llvm/llvm-project/pull/71029