FunctionDefinitionMacro constructor Null safety

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

FunctionDefinitionMacro class

1. Constructors
2. FunctionDefinitionMacro
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. visitFunctionDefinition
10. Operators
11. operator ==