Don't allow __attribute__((common)) in C++.  PR16330.

llvm-svn: 184493
diff --git a/clang/test/SemaCXX/attr-common.cpp b/clang/test/SemaCXX/attr-common.cpp
new file mode 100644
index 0000000..58b3013
--- /dev/null
+++ b/clang/test/SemaCXX/attr-common.cpp
@@ -0,0 +1,3 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+__attribute__((common)) int x; // expected-error {{common attribute is not supported in C++}}