Disable the "'extern' variable has an initializer" warning in C++,
since it makes sense there to have const extern variables. Fixes
PR6495.

llvm-svn: 101818
diff --git a/clang/test/SemaCXX/storage-class.cpp b/clang/test/SemaCXX/storage-class.cpp
new file mode 100644
index 0000000..a31e67b
--- /dev/null
+++ b/clang/test/SemaCXX/storage-class.cpp
@@ -0,0 +1,2 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+extern const int PR6495 = 42;