Removed error on naked, not fully complete, but I'll be doing more work on it during this Christmas, and some things do work.

Fixed taking delegate of final class method. see mini/delegate3.d.

gen/classes.cpp

@@ -1260,6 +1260,7 @@ LLValue* DtoVirtualFunctionPointer(DValue* inst, FuncDeclaration* fdecl)
 {
     // sanity checks
     assert(fdecl->isVirtual());
+    assert(!fdecl->isFinal());
     assert(fdecl->vtblIndex > 0); // 0 is always ClassInfo/Interface*
     assert(inst->getType()->toBasetype()->ty == Tclass);