Printing for using directives, e.g.,

  using namespace std::debug;

Extended UsingDirectiveDecl to store the nested-name-specifier that
precedes the nominated namespace.

llvm-svn: 72614
diff --git a/clang/test/Coverage/ast-printing.cpp b/clang/test/Coverage/ast-printing.cpp
new file mode 100644
index 0000000..10d01c7
--- /dev/null
+++ b/clang/test/Coverage/ast-printing.cpp
@@ -0,0 +1,6 @@
+// RUN: clang-cc --fsyntax-only %s &&
+// RUN: clang-cc --ast-print %s &&
+// RUN: clang-cc --ast-dump %s
+// FIXME: clang-cc --ast-print-xml -o %t %s
+
+#include "cxx-language-features.inc"