* (bugfix): emplace_back may reallocate, make cast_op ptr detached

* fix: wrong op sequence will cause node in graph not added
Co-authored-by: N--get <zhaoying@cambricon.com>
Co-authored-by: Ndingminghui <dingminghui@cambricon.com>

subgraph will rebuild while batchsize changable is on and encounter a
unsupported operator. graph will be destructed and recreated, in which Nan
hw perf log is printed

before c++11: `iterator erase( iterator pos );`
after c++11: `iterator erase( const_iterator pos );`

(ref): insert trans before and after transpose

caused by wrong data type in io_copy