[llvm] [CodeGen][ARM64EC] Add support for hybrid_patchable attribute. (PR #92965)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic commented:

Maybe also add a tests with varargs and sret to make sure the musttail call correctly preserves all the relevant registers.

https://github.com/llvm/llvm-project/pull/92965