33761df961
This reverts commit e9de32fd159d30cfd6fcc861b57b7e99ec2742ab due to multiple performance regressions observed across downstream Numba benchmarks (https://github.com/llvm/llvm-project/issues/138509#issuecomment-3193855772). While avoiding non-trivial unswitches on newly-cloned loops helps mitigate the pathological case reported in https://github.com/llvm/llvm-project/issues/138509, it may as well make the IR less friendly to vectorization / loop- canonicalization (in the test reported, previously no select with loop-carried dependence existed in the new specialized loops), leading the abovementioned approach to be reconsidered.