Add support for running our test suite against MSVC's STL

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292326 91177308-0d34-0410-b5e6-96231b3b80d8

test/support/MoveOnly.h

@@ -41,8 +41,9 @@ namespace std {
 
 template <>
 struct hash<MoveOnly>
-    : public std::unary_function<MoveOnly, std::size_t>
 {
+    typedef MoveOnly argument_type;
+    typedef size_t result_type;
     std::size_t operator()(const MoveOnly& x) const {return x.get();}
 };