[UNITY][Pass] Remove redundant reshape

[sjain58]

In Mobilenet float32, we see this sequence of ops:

%179 = squeeze(%178, axis=[2, 3]) /* ty=Tensor[(1, 1001), float16] span=MobilenetEdgeTPU/Logits/Squeeze:0:0 /;
%180 = reshape(%179, newshape=[-1, 1001]) / ty=Tensor[(1, 1001), float16] span=MobilenetEdgeTPU/Predictions/
Reshape:0:0 */;

which later gets transformed to

lv171 = R.call_tir(cls.primfunc_hmx_conv2d26_add20, (lv169, metadata["relax.expr.Constant"][116], metadata["relax.expr.Constant"][117]), out_sinfo=R.Tensor((1, 1001, 1, 1), dtype="float16"))
lv172: R.Tensor((1, 1001), dtype="float16") = R.reshape(lv171, R.shape([1, 1001]))
lv173: R.Tensor((1, 1001), dtype="float16") = R.reshape(lv172, R.shape([1, 1001]))

We can eliminate the redundant reshape.

lv171 = R.call_tir(cls.primfunc_hmx_conv2d26_add20, (lv169, metadata["relax.expr.Constant"][116], metadata["relax.expr.Constant"][117]), out_sinfo=R.Tensor((1, 1001, 1, 1), dtype="float16"))
lv173: R.Tensor((1, 1001), dtype="float16") = R.reshape(lv171, R.shape([1, 1001]))

[Lunderberg]

Thank you for the changes, and I like the implementation! I just have a couple of nitpicks remaining on it.

(FYI, it looks like the CI is currently stalled on lint checks, with an unused import tvm.)

[Lunderberg]

Thank you for making the changes, and looks good to me!