[mlir] [IR] Allow zero strides in StridedLayoutAttr (#116463)

Disabling memrefs with a stride of 0 was intended to prevent internal
aliasing, but this does not address all cases : internal aliasing can
still occur when the stride is less than the shape.

On the other hand, a stride of 0 can be very useful in certain
scenarios. For example, in architectures that support multi-dimensional
DMA, we can use memref::copy with a stride of 0 to achieve a broadcast
effect.

This commit removes the restriction that strides in memrefs cannot be 0.