Remove C++14-isms from C++11 tests

	* testsuite/20_util/reference_wrapper/lwg2993.cc: Fix C++11 test to
	not use C++14 feature.
	* testsuite/23_containers/list/68222_neg.cc: Likewise.

From-SVN: r263801

libstdc++-v3/ChangeLog

 2018-08-23  Jonathan Wakely  <jwakely@redhat.com>
 
+	* testsuite/20_util/reference_wrapper/lwg2993.cc: Fix C++11 test to
+	not use C++14 feature.
+	* testsuite/23_containers/list/68222_neg.cc: Likewise.
+
 	* testsuite/21_strings/basic_string/init-list.cc:
 	Require cxx11-abi.
 	* testsuite/experimental/polymorphic_allocator/pmr_typedefs_match.cc:

libstdc++-v3/testsuite/20_util/reference_wrapper/lwg2993.cc

@@ -51,5 +51,5 @@ test02()
 
   // error: no member 'type' because the conditional
   // expression is ill-formed
-  using t = std::common_type_t<std::reference_wrapper<int>, int>;
+  using t = typename std::common_type<std::reference_wrapper<int>, int>::type;
 }

libstdc++-v3/testsuite/23_containers/list/68222_neg.cc

@@ -26,10 +26,10 @@ test01()
   const std::list<int> nums = { 1, 2, 3, 4 };
 
   // Grab the iterator type.
-  using list_itr_type = decltype( std::cbegin( nums ) );
+  using list_itr_type = decltype( std::begin( nums ) );
 
   // Confirm cend returns the same type.
-  static_assert( std::is_same< decltype( std::cend( nums ) ), list_itr_type >::value, "" );
+  static_assert( std::is_same< decltype( std::end( nums ) ), list_itr_type >::value, "" );
 
   // The list's iterator type provides a well-formed non-member operator-() with valid return type (long int)
   using substraction_type