[compiler-rt] [llvm] [AArch64] Implement INIT/ADJUST_TRAMPOLINE (PR #70267)

[Carlos Eduardo Seo via llvm-commits]

ceseo wrote:

> Probably fixes #56625 too? _**Edit**_: not yet, if this is limited to Linux

Yes, we need to sort out the nest parameter register for Windows and macOS. Both use `x18` as the platform register. So this is Linux only for now.

https://github.com/llvm/llvm-project/pull/70267