Improve on reporting ambiguity involving built-in candidates.
I still don't like it but it is improvement over what we had.

llvm-svn: 83603
diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index f85c1a8..9f6db69 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -906,7 +906,9 @@
                                        SourceLocation Loc,
                                        OverloadCandidateSet::iterator& Best);
   void PrintOverloadCandidates(OverloadCandidateSet& CandidateSet,
-                               bool OnlyViable);
+                         bool OnlyViable,
+                         BinaryOperator::Opcode Opc=(BinaryOperator::Opcode)0,
+                         SourceLocation Loc=SourceLocation());
 
   FunctionDecl *ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
                                                    bool Complain);