Shape inference for SparseToDense in ExpertCombiner
Summary: Adding shape inference for SpraseToDense. Proposal impl of shape inference only works when data_to_infer_dim is given, otherwise SpraseToDense output dimension depends on max value of input tensor
Test Plan:
buck test //caffe2/caffe2/python:sparse_to_dense_test
buck test //caffe2/caffe2/python:hypothesis_test -- test_sparse_to_dense
Dper3 Changes:
f204594813
buck test dper3/dper3_models/ads_ranking/model_impl/sparse_nn/tests:sparse_nn_lib_test
Reviewed By: zhongyx12, ChunliF
Differential Revision: D22479511
fbshipit-source-id: 8983a9baea8853deec53ad6f795c874c3fb93de0
