#include <test_macros.h> in all the regex tests, and remove all mentions of __cpluplus (use TEST_STD_VERS and/or XFAIL instead). No functional change

llvm-svn: 267567
diff --git a/libcxx/test/std/re/re.traits/default.pass.cpp b/libcxx/test/std/re/re.traits/default.pass.cpp
index defadd9..b1e2358 100644
--- a/libcxx/test/std/re/re.traits/default.pass.cpp
+++ b/libcxx/test/std/re/re.traits/default.pass.cpp
@@ -19,6 +19,7 @@
 #include <regex>
 #include <cassert>
 
+#include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
 int main()