The expansion of `memref.atomic_rmw` into a `memref.generic_atomic_rmw`
for floating-point min/max operations is no longer necessary as those
are now supported by the LLVM dialect and LLVM IR.
Furthermore, combining this expansion with direct lowering of
`generic_atomic_rmw` could leads to invalid LLVM dialect IR with
`cmpxchg` operating on floating-point values that it does not support.
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