This is an attempt to make our definition of "override" and "final overrider" more consistent with its use, and includes some small cleanups along the way.

In [class.cdtor] p4 we have the following wording:

[...] the function called is the final overrider in the constructor's or destructor's class [...]

We also have the following wording in [expr.call] p3:

Otherwise, its final overrider in the dynamic type of the object expression is called

In both of these cases, we refer to the final overrider relative to another class. Changing the definition to match the use here seems reasonable. The approach taken here is to define the final overrider of a function relative to a class (as far as I can tell this wording shouldn't change semantics; it accounts for redeclared members not being members of the derived class).

There also was a missing \grammarterms around ref-qualifier, and cv-qualification was changed to be cv-qualifier-seq to match function declarators. Since we no longer need to consider virtual functions to override themselves, it allows us to simplify the wording a bit in other places.