Location of templates should refer to templated declaration

[alandefreitas]

When the function or record is a template, the location we extract refers to the template rather than the name in the templated declaration.

So, while for any other symbol the location points to the symbol name, as in this warning:

/__w/mrdocs/mrdocs/beman-optional/include/beman/optional/optional.hpp:105:22:
    1) beman::optional::nullopt_t::Tag::tag: Missing documentation for enum value
  105 |     enum class Tag { tag };
      |                      ^~~~~~

The location of templates refers to the template declaration, as in this warning:

    1) beman::optional::optional::or_else: Missing documentation for parameter 'f'
  1807 |     template <class F>
       |     ^~~~~~~~~~~~~~~~~~

To fix this, when the Decl is a template, we would need to use the Decl for the templated declaration instead of the Decl for the template declaration in:

ASTVisitor::populate(SourceInfo& I, DeclTy const* D)

before calling:

ASTVisitor::populate(SourceInfo& I, clang::SourceLocation const loc, bool const definition, bool const documented)

[mizvekov]

Though in your second example, it would be better to point to the parameter 'f' instead.

[alandefreitas]

Though in your second example, it would be better to point to the parameter 'f' instead.

Heh... True. I was trying to think one problem at a time, but that's true. :)