[llvm] [AArch64] Use the same fast math preservation for MachineCombiner reassociation as X86/PowerPC/RISCV. (PR #72820)

[Craig Topper via llvm-commits]

topperc wrote:

> Could this be used as the default implementation?

I think so. I haven't audited which other targets have enabled reassociation without this hook. I can do that.

https://github.com/llvm/llvm-project/pull/72820