Replace use of C++14 std::exchange in C++11 testcase

	* testsuite/28_regex/traits/char/user_defined.cc: Replace uses of
	C++14 std::exchange function.

From-SVN: r243354

libstdc++-v3/ChangeLog

 2016-12-07  Jonathan Wakely  <jwakely@redhat.com>
 
+	* testsuite/28_regex/traits/char/user_defined.cc: Replace uses of
+	C++14 std::exchange function.
+
 	* testsuite/util/testsuite_hooks.h (THROW): Define.
 	* testsuite/util/replacement_memory_operators.h: Include
 	testsuite_hooks.h and use THROW macro.

libstdc++-v3/testsuite/28_regex/traits/char/user_defined.cc

@@ -72,13 +72,15 @@ test01()
     VERIFY(!called_transform);
     basic_regex<char, MyRegexTraits<char>> re("[a]", regex::collate);
     VERIFY(regex_match("a", re));
-    VERIFY(exchange(called_transform, false));
+    VERIFY(called_transform);
+    called_transform = false;
   }
   {
     VERIFY(!called_nocase);
     basic_regex<char, MyRegexTraits<char>> re("[a]", regex::icase);
     VERIFY(regex_match("A", re));
-    VERIFY(exchange(called_nocase, false));
+    VERIFY(called_nocase);
+    called_nocase = false;
   }
   {
     basic_regex<char, MyRegexTraits<char>> re("[T-f]", regex::icase);