JCClassDecl cd = make.at(tree.pos).ClassDef(
make.Modifiers(PUBLIC | ABSTRACT),
tree.name, List.<JCTypeParameter>nil(),
extending, implementing, List.<JCTree>nil());
ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
Assert.check((c.flags() & COMPOUND) != 0);
cd.sym = c;
c.sourcefile = env.toplevel.sourcefile;
// ... and attribute the bound class
c.flags_field |= UNATTRIBUTED;