[mlir][Linalg] Disable fusion of reshape with elementwise ops for purely dynamic cases.
`tensor.collapse_shape` op when fused with a consumer elementwise
`linalg.generic` operation results in creation of tensor.expand_shape
ops. In purely dynamic cases this can end up with a dynamic dimensions
being expanded to more than one dynamic dimension. This is disallowed
by the semantics of `tensor.expand_shape` operation. (While the
transformation is itself correct, its a gap in the specification of
`tensor.expand_shape` that is the issue). So disallow fusions which
result in such a pattern.
Differential Revision: https://reviews.llvm.org/D116703