[llvm] [AArch64] Optimize when storing symmetry constants (PR #93717)

[David Green via llvm-commits]

https://github.com/davemgreen approved this pull request.

Yeah I agree about big endian.

I should note that every time we try and implement these backend optimizations at the mir level something ends up going wrong, so please keep an eye out for any problems this might cause.

LGTM

https://github.com/llvm/llvm-project/pull/93717