ConstructorDefinition constructor Null safety

1. macro_builder
2. definition
3. ConstructorDefinition
4. ConstructorDefinition constructor

ConstructorDefinition class

1. Constructors
2. ConstructorDefinition
3. Properties
4. definingClass
5. hashCode
6. isAbstract
7. isExternal
8. isFactory
9. isGetter
10. isSetter
11. name
12. namedParameters
13. positionalParameters
14. returnType
15. runtimeType
16. typeParameters
17. Methods
18. noSuchMethod
19. toString
20. Operators
21. operator ==