Function FuseListStack

tools/converter/source/torch/torchOptimize.cpp:239–263

We rewrite something like: x = ListConstruct(v1, v2, v3) y = stack(y, axis) to: y = stack(v1, v2, v3, axis) */

        y = stack(v1, v2, v3, axis)
*/
void FuseListStack(Block* block) {
    for (auto it = block->nodes().begin(); it != block->nodes().end();) {
        auto* node = *it;
        it++;

        for (Block* sub_block : node->blocks()) {
            FuseListUnpack(sub_block);
        }
        std::set<NodeKind> fusekind = {
            aten::stack
        };
        if (it->kind() == aten::stack) {
            auto input = it->input(0)->node();
            if (input->kind() == prim::ListConstruct) {
                auto axis = it->input(1);
                it->removeAllInputs();
                for (int i = 0; i < input->inputs().size(); i++) {
                    it->addInput(input->input(i));
                }
                it->addInput(axis);
                input->destroy();
            }
        }
    }
}
/*
 We rewrite something like:
    %y : int, %z : int = prim::Loop(%6, %2, %y.1, %z.1) # <ipython-input-14-d0a2ead71c2a>:6:4