Fix vtable mapping handling so that it doesn't ignore mappings of handlers from attributes.
Fix vtable mapping handling so that it doesn't ignore mappings of handlers from attributes.

cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp