[llvm] [M68k] Add remaining addressing modes for Atomic operations (PR #115523)

[John Paul Adrian Glaubitz via llvm-commits]

glaubitz wrote:

Ah, I think I need to build a bootstrap compiler first which includes the change to `rustc_codegen_ssa` as otherwise it won't be possible to build any artifacts for m68k.

https://github.com/llvm/llvm-project/pull/115523