[doclint] doclint is showing error on anchor already defined when it's not

Let's build JDK with doclint turned on.

We'll see this error line:
/export/doclint/jdk/src/share/classes/java/awt/geom/Path2D.java:777: error: anchor already defined: Path2DSerialData

It is true, that this anchor is already defined, but it is defined in Path2D class itself, but this anchor (which is shown in bug message) is defined in it's subclass: Path2D.Float and it generated absolutel independent HTML and there is no coliision between these two anchors.

I think it is wrong behavior and should be fixed.