CommentExpander

The raw doc comment of symbol sym, minus usecase and define sections, augmented by missing sections of an inherited doc comment. If a symbol does not have a doc comment but some overridden version of it does, the doc comment of the overridden version is copied instead.

The position of the raw doc comment of symbol sym, or NoPosition if missing If a symbol does not have a doc comment but some overridden version of it does, the position of the doc comment of the overridden version is returned instead.

Expand inheritdoc tags

• for the main comment we transform the inheritdoc into the super variable, and the variable expansion can expand it further
• for the param, tparam and throws sections we must replace comments on the spot

This is done separately, for two reasons:

1. It takes longer to run compared to merge
2. The inheritdoc annotation should not be used very often, as building the comment from pieces severely impacts performance

The cooked doc comment of symbol sym after variable expansion, or "" if missing.

Lookup definition of variable.