[llvm] [VectorCombine] Fold concat(binop(a,c), binop(b,d)) -> binop(concat(a,b), concat(c,d)) for i1 vectors (PR #206087)

[Yingwei Zheng via llvm-commits]

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+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
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dtcxzyw wrote:

llc doesn't run the VectorCombine pass. This test doesn't reflect the code change. https://godbolt.org/z/7e1anKxMM


https://github.com/llvm/llvm-project/pull/206087