[AArch64] Mark AESD and AESE instructions as commutative. (#83390)

This come from
https://discourse.llvm.org/t/combining-aes-and-xor-can-be-improved-further/77248.

These instructions start out with:
```
  XOR Vd, Vn
  <some complicated math>
```
The initial XOR means that they can be treated as commutative, removing
some of the unnecessary mov's introduced during register allocation.