[MLIR][Affine] Improve sibling fusion - handle memrefs from memref defining nodes (#149641)
Improve sibling fusion - handle memrefs from memref defining nodes which
were not being considered.
Remove the unnecessary restriction from MDG memref edge iteration to
restrict to affine.for ops. Nodes in the MDG could be other ops as well.
Fixes: https://github.com/llvm/llvm-project/issues/61825