This patch is part of a larger simplification effort of vector transfer
operations. It removes the flag `lower-permutation-maps` from
VectorToSCF conversion and enables the lowering of permutation maps
by default. This means that VectorToSCF will always lower permutation
maps to independent broadcast/transpose operations before lowering
vector operations to SCF.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D138742
This op significantly improves transfor dialect usage when using vector abstractions.
It also brings us closer to writing simple end-to-end unit tests that guard against subtle regressions in how patterns combine.
Differential Revision: https://reviews.llvm.org/D138723
