[llvm] [MachineLateInstrsCleanup] Reuse redundant spill-slot reloads (PR #220180)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

The allocator already does redundant spill cleanup optimizations on its own. Why were these missed that requires a cleanup pass?

https://github.com/llvm/llvm-project/pull/220180