The current approach is convervative in which whenever there is a
non-normalizable operations in a function will the function be labelled
as non-normalizable. It means it requires that all operations must have
MemRefsNormalizable trait.
This patch relaxes the requirement that if the memref map layouts of a
non-normalizable operation are identity, this operation does not block
the normalization of the other operations in the same function.
Reviewed By: bondhugula
Differential Revision: https://reviews.llvm.org/D125854
183c4a391e