For example, given:
enum __attribute__((deprecated)) T *p;
-ast-print produced:
enum T *p;
The attribute was lost because the enum forward decl was lost.
Another example is the loss of enum forward decls from C++ namespaces
(in MS compatibility mode).
The trouble was that the EnumDecl node was suppressed, as revealed by
-ast-dump. The suppression of the EnumDecl was intentional in
r116122, but I don't understand why. The suppression isn't needed for
the test suite to behave.