[llvm] [DAG] Fold extract_subvector(insert_subvector(x, y, c1), c2) --> extract_subvector(y,c2-c1) (PR #87925)

[Steven Johnson via llvm-commits]

steven-johnson wrote:

Enclosed is an IR file that will replicate the crash when run through llc.
[test_op_frecpe_float32_x8_0.zip](https://github.com/llvm/llvm-project/files/14984651/test_op_frecpe_float32_x8_0.zip)


https://github.com/llvm/llvm-project/pull/87925