[clang] [llvm] [CodeGen][arm64e] Add methods and data members to Address, which are needed to authenticate signed pointers (PR #67454)

[Akira Hatanaka via cfe-commits]

ahatanak wrote:

I'm not sure `extractRawPointerFromAddress` conveys the fact that the function might do code-gen instead of just returning some pointer. I wonder if there's a better name.

`computeRawPointerFromAddress`
`genRawPointerFromAddress`
`generateRawPointerFromAddress`
`codeGenRawPointerFromAddress`

Thoughts?

https://github.com/llvm/llvm-project/pull/67454