[llvm] [RISCV] Add load/store clustering in post machine schedule (PR #111504)

[via llvm-commits]

BoyaoWang430 wrote:

> > > createGenericSchedLive
> > 
> > 
> > I think the reason is you are using pre-ra scheduler here.
> 
> Thank you - the problem was indeed me being too eager with copy and paste and failing to switch to `createGenericSchedPostRA`. Now I've done that though, I see zero codegen changes within the in-tree unit tests.

We also made the same mistake when we first tried to add this by copy-paste. I will add some MIR tests these days to demonstrate the difference that enabling load/store clustering in the post machine scheduler can make. 

https://github.com/llvm/llvm-project/pull/111504