Added comprehensive result verification and assertions to ensure correctness:
go/token demo:
- Verify Pos values and IsValid() results
- Check token string representations
- Validate keyword detection (IsKeyword())
- Assert operator precedence relationships
- Verify file and position operations
go/types demo:
- Validate basic type kinds
- Check object names and types (Var, Const, Func, TypeName)
- Verify package path and name
- Assert interface method counts and names
- Check struct field counts, names, and types
- Validate signature params and results
- Verify tuple, array, slice, pointer, map, and chan properties
All demos now fail fast with panic() if results don't match expected values,
providing better test coverage than just printing output.
Generated with [codeagent](https://github.com/qbox/codeagent)
Co-authored-by: luoliwoshang <51194195+luoliwoshang@users.noreply.github.com>
ebd041082b