Remove uses of std::binary_function, removed in C++17.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@298663 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/TypeOrdering.h

@@ -26,7 +26,7 @@
 namespace clang {
 
 /// \brief Function object that provides a total ordering on QualType values.
-struct QualTypeOrdering : std::binary_function<QualType, QualType, bool> {
+struct QualTypeOrdering {
   bool operator()(QualType T1, QualType T2) const {
     return std::less<void*>()(T1.getAsOpaquePtr(), T2.getAsOpaquePtr());
   }

include/clang/Basic/SourceLocation.h

@@ -321,8 +321,7 @@ public:
   }
 
   /// \brief Comparison function class, useful for sorting FullSourceLocs.
-  struct BeforeThanCompare : public std::binary_function<FullSourceLoc,
-                                                         FullSourceLoc, bool> {
+  struct BeforeThanCompare {
     bool operator()(const FullSourceLoc& lhs, const FullSourceLoc& rhs) const {
       return lhs.isBeforeInTranslationUnitThan(rhs);
     }