Add test that _LIBCPP_VERSION matches __libcpp_version

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290445 91177308-0d34-0410-b5e6-96231b3b80d8

test/libcxx/libcpp_version.pass.cpp

@@ -0,0 +1,28 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// Test that the __libcpp_version file matches the value of _LIBCPP_VERSION
+
+#include <__config>
+
+#ifndef _LIBCPP_VERSION
+#error _LIBCPP_VERSION must be defined
+#endif
+
+static const int libcpp_version =
+#include <__libcpp_version>
+;
+
+static_assert(_LIBCPP_VERSION == libcpp_version,
+              "_LIBCPP_VERSION doesn't match __libcpp_version");
+
+int main() {
+
+}