[llvm] [RISCV] Rematerialize load (PR #73924)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

Don't understand why RISCV is overloading this in the first place; it looks like it's augmented a bunch of generic heuristics without any real target specific handling 

https://github.com/llvm/llvm-project/pull/73924