Method delete_handle

imperative/src/impl/ops/rng.cpp:26–34

    }

    size_t delete_handle(Handle handle) {
        size_t removed = 0;
        if (!is_finalized()) {
            MGB_LOCK_GUARD(m_mtx);
            removed = m_handle2ops.erase(handle);
        }
        static_cast<HandleFactory*>(this)->do_delete_handle(handle);
        return removed;
    }

    template <typename DnnOp>
    auto get_dnn_op(Handle handle, OpTypeInfo tpinfo, CompNode cn) {