The Standard Doclet produces incorrect method signatures when documenting a class that extends a package private super type. This
is a side effect of the fix for JDK-8157000. The logic for that enhancement should check if it is a simple override AND the super-type is documentable before flagging the methods in the sub-type as an overriding method.

The classes known to suffer from this issue as java.lang.StringBuffer and java.lang.StrinBuilder, the super-type is
java.lang.AbstractStringBuilder which is package private.