[compiler-rt] [compiler-rt][builtins]Fix complex division for aarch64 (PR #106664)

[Eli Friedman via llvm-commits]

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

I didn't realize there's actually an `#ifdef aarch64` here; it seems like that's just introducing gratuitous differences for no reason.  Getting rid of that seems fine.

https://github.com/llvm/llvm-project/pull/106664