A system has its own STRING class, excluding the one from EiffelBase.
This STRING class does not inherit from TO_SPECIAL [CHARACTER], which
causes a VEEN error.  After the compiler correctly detects this error,
the missing inheritance clause is added to STRING.  The compiler then
reports a bogus VGCC(5) error in class MISMATCH_CORRECTOR.

Discovered in release 5.4.0610.