Implement P0754R2: The <version> header.

llvm-svn: 329075
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 082229eb0fd5cdf98c6c15ce697ab93eb4c41b42
diff --git a/include/version b/include/version
new file mode 100644
index 0000000..23a872e
--- /dev/null
+++ b/include/version
@@ -0,0 +1,25 @@
+// -*- C++ -*-
+//===--------------------------- version ----------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_VERSIONH
+#define _LIBCPP_VERSIONH
+
+/*
+    version synopsis
+
+*/
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#endif  // _LIBCPP_VERSIONH