Allow implicit 'close your eyes' of native methods. This will hopefully fix issue 3466.

vm/intermediate_language.h

 // 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.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 824 matching lines @@
   NativeFunction native_c_function() const {
     return ast_node_.native_c_function();
   }
 
   intptr_t argument_count() const { return ast_node_.argument_count(); }
 
   bool has_optional_parameters() const {
     return ast_node_.has_optional_parameters();
   }
 
+  bool is_native_instance_closure() const {
+    return ast_node_.is_native_instance_closure();
+  }
+
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
  private:
   const NativeBodyNode& ast_node_;
   const intptr_t try_index_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeCallComp);
 };
 
 
@@ skipping 1565 matching lines @@
   const GrowableArray<BlockEntryInstr*>& block_order_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_