Remove signature classes from the VM.

runtime/vm/cha.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/cha.h"
 #include "vm/class_table.h"
 #include "vm/flags.h"
 #include "vm/freelist.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
@@ skipping 31 matching lines @@
 
 
 bool CHA::HasSubclasses(intptr_t cid) const {
   const ClassTable& class_table = *thread_->isolate()->class_table();
   Class& cls = Class::Handle(thread_->zone(), class_table.At(cid));
   return HasSubclasses(cls);
 }
 
 
 bool CHA::IsImplemented(const Class& cls) {
-  // Signature classes have different type checking rules.
-  ASSERT(!cls.IsSignatureClass());
+  // Function type aliases have different type checking rules.
+  ASSERT(!cls.IsTypedefClass());
   // Can't track dependencies for classes on the VM heap since those are
   // read-only.
   // TODO(fschneider): Enable tracking of CHA dependent code for VM heap
   // classes.
   if (cls.InVMHeap()) return true;
 
   return cls.is_implemented();
 }
 
 
@@ skipping 26 matching lines @@
       return true;
     }
     if (HasOverride(direct_subclass, function_name)) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace dart