[llvm] [SystemZ] Don't lower float/double ATOMIC_[LOAD|STORE] to [LOAD|STORE] (PR #75879)

[Jonas Paulsson via llvm-commits]

JonPsson1 wrote:

> > We could do something similar with the atomic_store:s, like z_store, but it seems the handling of stores is quite alright like this, or?
> 
> Stores should be similarly handled, you can also use PatFrags

Ideally, yes. This is however much less of a hack than what the handling of loads was before since the store gets selected after its operands and therefore has everything ready.

https://github.com/llvm/llvm-project/pull/75879