1. No id follow '[CNode]';
2. Miss TraceTransform info after TransformClone().

1. Use static 'name' and 'symbol' for TraceInfo, avoid copy them;
2. Refactor DebugInfo, move 'debug_id' down to GraphDebugInfo;
3. Make Location, TraceContext immutable;
4. Optimize trace context stack, use value instead of shared_ptr;
5. TraceInfo, DebugInfo no longer inherit from Base.

1. Refactor and optimize code for Cloner and its clients;
2. Directly clone debug info instead of using TraceGuard;
3. Optimize TraceInfo classes.

1. 'defined' -> 'defines';
2. 'Gets' -> 'Get';
3. 'Sets' -> 'Set'.

endless issue.