[llvm] [NFC][AsmPrinter] Refactor AsmPrinter and AArch64AsmPrinter to prepare for jump table partitions on aarch64 (PR #125993)

[David Green via llvm-commits]

https://github.com/davemgreen approved this pull request.

I think this looks OK. LGTM

https://github.com/llvm/llvm-project/pull/125993