A system has a class B that inherits from class A and redefines a
function into an attribute.  After the system is frozen, class B is
changed so that it renames the function instead of redefining it, but
it still includes the attribute that was the redefinition.  When the
system is refrozen, the resulting C code compiles, but will not link
due to an undefined symbol.

Reported by Manu on 3 January 2002.