before optimising function result assignment, because at this point the
    hidden self parameter is not yet inserted (mantis #12597)
  * changed ttypeconvnode.actualtargetnode to use the same logic as what
    is used to determine whether something can be assigned to the result
    of a type conversion (so the above check also works if the methodpointer
    contains a typecast to a different object type)

git-svn-id: trunk@12038 -