Don't assume at least one closure function is encountered before tree-shaking. Allow…

runtime/vm/object.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_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1165 matching lines @@
   void AddFunction(const Function& function) const;
   void RemoveFunction(const Function& function) const;
   intptr_t FindFunctionIndex(const Function& function) const;
   RawFunction* FunctionFromIndex(intptr_t idx) const;
   intptr_t FindImplicitClosureFunctionIndex(const Function& needle) const;
   RawFunction* ImplicitClosureFunctionFromIndex(intptr_t idx) const;
 
   RawGrowableObjectArray* closures() const {
     return raw_ptr()->closure_functions_;
   }
+  void set_closures(const GrowableObjectArray& value) const;
   void AddClosureFunction(const Function& function) const;
   RawFunction* LookupClosureFunction(intptr_t token_pos) const;
   intptr_t FindClosureIndex(const Function& function) const;
   RawFunction* ClosureFunctionFromIndex(intptr_t idx) const;
 
   RawFunction* LookupDynamicFunction(const String& name) const;
   RawFunction* LookupDynamicFunctionAllowPrivate(const String& name) const;
   RawFunction* LookupStaticFunction(const String& name) const;
   RawFunction* LookupStaticFunctionAllowPrivate(const String& name) const;
   RawFunction* LookupConstructor(const String& name) const;
@@ skipping 6964 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_