[llvm] [AArch64] Run optimizeTerminators earlier too. (PR #170907)

[David Green via llvm-commits]

davemgreen wrote:

I hadn't checked that. We run more copy-propagation at -O3, so it might already do OK there now, after the previous patch:
https://godbolt.org/z/b4Yjc1Gq5

https://github.com/llvm/llvm-project/pull/170907