A class A has a deferred routine with an argument anchor to an
attribute `a'.  A second class B inherits A and has an identical
deferred routine with the same name, where the routine in B is also
anchored to `a'.  Class C inherits both A and B.  The compiler
incorrectly reports a VDJR error and a VD43 warning.

Reported by Manu for release 5.2.1102.