test: Mark 316 tests as XFAIL to rename to xfail.pass.cpp.

test/re/re.regex/re.regex.locale/imbue.xfail.pass.cpp

@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <regex>
+
+// template <class charT, class traits = regex_traits<charT>> class basic_regex;
+
+// locale_type imbue(locale_type loc);
+
+#include <regex>
+#include <locale>
+#include <cassert>
+
+int main()
+{
+    std::regex r;
+    std::locale loc = r.imbue(std::locale("en_US"));
+    assert(loc.name() == "C");
+    assert(r.getloc().name() == "en_US");
+    loc = r.imbue(std::locale("C"));
+    assert(loc.name() == "en_US");
+    assert(r.getloc().name() == "C");
+}