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/sequences/vector.bool/reference.swap.pass.cpp

@@ -15,6 +15,8 @@
 #include <vector>
 #include <cassert>
 
+#include "test_macros.h"
+
 int main()
 {
 
@@ -25,7 +27,7 @@ int main()
 	std::vector<bool>::reference r1 = v[0];
 	std::vector<bool>::reference r2 = v[3];
 
-#if __has_feature(cxx_noexcept)
+#if TEST_STD_VER >= 11
     static_assert((noexcept(v.swap(r1,r2))), "");
 #endif
 
@@ -34,4 +36,4 @@ int main()
 	v.swap(r1, r2);
 	assert( r1);
 	assert(!r2);
-}
+}