Implement P0004R1 'Remove Deprecated iostreams aliases'

llvm-svn: 251618
diff --git a/libcxx/test/std/depr/depr.ios.members/io_state.pass.cpp b/libcxx/test/std/depr/depr.ios.members/io_state.pass.cpp
index 15bfbf1..6b362d0 100644
--- a/libcxx/test/std/depr/depr.ios.members/io_state.pass.cpp
+++ b/libcxx/test/std/depr/depr.ios.members/io_state.pass.cpp
@@ -15,11 +15,16 @@
 //     typedef T1 io_state;
 // };
 
+//  These members were removed for C++17
+
+#include "test_macros.h"
 #include <strstream>
 #include <cassert>
 
 int main()
 {
+#if TEST_STD_VER <= 14
     std::strstream::io_state b = std::strstream::eofbit;
     assert(b == std::ios::eofbit);
+#endif
 }