[mlir][vector] Add fold to transfer_{read,write} vector<1xT> (#196598)
vector.transfer_read and vector.transfer_write's permutations maps are
irrelevant with vector<1xT>. This pattern unblocks lowerings to
vector.load and vector.store.
Assisted-By: Claude Opus 4.6
GitOrigin-RevId: 8c493f558686d01223a6f4ac8d17ea4b16055557
See https://mlir.llvm.org/ for more information.