[lld] [lld-macho][arm64] Enhance safe ICF with thunk-based deduplication (PR #106573)

[via llvm-commits]

alx32 wrote:

This triggers a static assert on GCC: https://github.com/llvm/llvm-project/issues/107511
```
   24 | static_assert(sizeof(void *) != 8 || sizeof(Defined) == 88,
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
```
Looking into now. Will forward fix / revert soon.

https://github.com/llvm/llvm-project/pull/106573