Proposed resolution:

Change the synopsis in [complex.syn]:

template<class T> complex<T> fabs(const complex<T>&);

Remove [complex.value.ops], p7:

template<class T> complex<T> fabs(const complex<T>& x);

-7- Effects: Behaves the same as C99 function cabs, defined in subclause 7.3.8.1.