Merging r168818: into the 3.2 release branch.

PR13098: If we're instantiating an overloaded binary operator and we could
determine which member function would be the callee from within the template
definition, don't pass that function as a "non-member function" to
CreateOverloadedBinOp. Instead, just rely on it to select the member function
for itself.

llvm-svn: 168830