[NNPA] A rewrite pattern to get dim directly from a zTensor without unstickification.

[tungld]

This patch is to add a rewriting pattern that removes zhigh.unstick when getting dimensions.

For example, the following code

%0 = "zhigh.Unstick"(%arg0) : (tensor<?x?x?xf16, #zhigh.layout<{dataLayout = "3D"}>>) -> tensor<?x?x?xf32>
%1 = "onnx.Dim"(%0) {axis = 1 : si64}: (tensor<?x?x?xf32>) -> tensor<1xi64>

will be replace by

"onnx.Dim"(%arg0) {axis = 1 : si64} : (tensor<?x?x?xf16, #zhigh.layout<{dataLayout = "3D"}>>) 

where the dimension is obtained directly from a zTensor without unstickifying the zTensor.

[AlexandreEichenberger]

LGTM, makes total sense

[jenkins-droid]

Jenkins Linux amd64 Build #13521 [push] Get dim directly from zT... started at 20:54

[jenkins-droid]

Jenkins Linux s390x Build #13548 [push] Get dim directly from zT... started at 21:54

[jenkins-droid]

Jenkins Linux ppc64le Build #12545 [push] Get dim directly from zT... started at 22:00

[jenkins-droid]

Jenkins Linux amd64 Build #13521 [push] Get dim directly from zT... failed after 58 min

[jenkins-droid]

Jenkins Linux s390x Build #13548 [push] Get dim directly from zT... passed after 1 hr 20 min

[jenkins-droid]

Jenkins Linux ppc64le Build #12545 [push] Get dim directly from zT... passed after 1 hr 57 min