// reshapes in many cases. More precisely, this function creates 1s matrix
// with appropriate shape to match with the shape of XlaDotV2 result.
// We didn't apply XlaEinsum or XlaDotV2 for this work, since it would loose
// the chance for constant folding later. We could try to add some
// postprocessing passes later to further optimize the graph after constant
// folding.