Summary:
SqueezeOp support to drop drop dims of size 1. MKLMemory now supports Reshape()
if the buffer is in plain layout, in which case just the dims and layouts are
modified similar to caffe2::Tensor. SqueezeOp takes care of converting the
input to plain layout if needed via an intermediate buffer before calling
Reshape().
Differential Revision: D6735656
fbshipit-source-id: 953309498370e1b8986e8c593bc6963f38036255