Replace __cplusplus comparisons and dialect __has_feature checks with TEST_STD_VER.

This is a huge cleanup that helps make the libc++ test suite more portable.
Patch from STL@microsoft.com. Thanks STL!


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@272716 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/containers/container.adaptors/stack/stack.special/swap_noexcept.pass.cpp

@@ -14,6 +14,8 @@
 
 // This tests a conforming extension
 
+// UNSUPPORTED: c++98, c++03
+
 #include <stack>
 #include <cassert>
 
@@ -21,11 +23,9 @@
 
 int main()
 {
-#if __has_feature(cxx_noexcept)
     {
         typedef std::stack<MoveOnly> C;
         C c1, c2;
         static_assert(noexcept(swap(c1, c2)), "");
     }
-#endif
 }