When we have a non-dependent expression such as

  A::f

that occurs within a non-static member function with a type-dependent
"this", don't consider this to be a case for introduction of an
implicit "(*this)." to refer to a specific member function unless we
know (at template definition time) that A is a base class of *this.

There is some disagreement here between GCC, EDG, and Clang about the
handling of this case. I believe that Clang now has the correct,
literal interpretation of the standard, but have asked for
clarification (c++std-core-15483).

llvm-svn: 89425