Before this, commenting is only possible on specific names, with this
the entire supported line is active (unless there are more grannular
comment contexts, for example, in the function prototype).
For example (commentable parts are marked with `^`):
```
// struct whatever {
// ...
// before this
const my_type_name *my_field_name[10];
// ^^^^^^^^^^^^^
// after this
const my_type_name *my_field_name[10];
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// ...
// };
```
It's the same for all the others, like segments, arguments, and so on.
This reworks NameBuilder to ease the transition to the system where
the model will be guaranteed to never contain any name collisions, both
between user-specified names and the automatic ones.
Ivan Krysak