[class.derived] Clean up cross-references.

Author: jensmaurer

source/classes.tex

@@ -3600,14 +3600,14 @@
 
 \pnum
 \begin{note}
-A base class subobject might have a layout\iref{basic.stc} different
+A base class subobject might have a layout different
 from the layout of a most derived object of the same type. A base class
 subobject might have a polymorphic behavior\iref{class.cdtor}
 different from the polymorphic behavior of a most derived object of the
-same type. A base class subobject may be of zero size\iref{class};
+same type. A base class subobject may be of zero size;
 however, two subobjects that have the same class type and that belong to
 the same most derived object must not be allocated at the same
-address\iref{expr.eq}.
+address\iref{intro.object}.
 \end{note}
 
 \rSec2[class.mi]{Multiple base classes}