Fix (optimizer) crashes in conditional nodes when result is not needed.

runtime/vm/flow_graph_builder.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_FLOW_GRAPH_BUILDER_H_
 #define VM_FLOW_GRAPH_BUILDER_H_
 
 #include "platform/assert.h"
 #include "platform/globals.h"
 #include "vm/allocation.h"
@@ skipping 459 matching lines @@
                           const intptr_t old_ctx_level,
                           JoinEntryInstr* target);
 
   void BuildAsyncJump(LocalVariable* old_context,
                       LocalVariable* continuation_result,
                       LocalVariable* continuation_error,
                       LocalVariable* continuation_stack_trace,
                       const intptr_t old_ctx_level,
                       JoinEntryInstr* target);
 
+  void BuildInstanceGetterConditional(InstanceGetterNode* node);
+  void BuildInstanceCallConditional(InstanceCallNode* node);
+
   Isolate* isolate() const { return owner()->isolate(); }
   Zone* zone() const { return owner()->zone(); }
 
  private:
   friend class TempLocalScope;  // For ReturnDefinition.
 
   // Helper to drop the result value.
   virtual void ReturnValue(Value* value) {
     Do(new DropTempsInstr(0, value));
   }
@@ skipping 28 matching lines @@
       : EffectGraphVisitor(owner), value_(NULL) { }
 
   // Visit functions overridden by this class.
   virtual void VisitAssignableNode(AssignableNode* node);
   virtual void VisitConstructorCallNode(ConstructorCallNode* node);
   virtual void VisitBinaryOpNode(BinaryOpNode* node);
   virtual void VisitConditionalExprNode(ConditionalExprNode* node);
   virtual void VisitLoadLocalNode(LoadLocalNode* node);
   virtual void VisitStoreIndexedNode(StoreIndexedNode* node);
   virtual void VisitInstanceSetterNode(InstanceSetterNode* node);
+  virtual void VisitInstanceGetterNode(InstanceGetterNode* node);
   virtual void VisitThrowNode(ThrowNode* node);
   virtual void VisitClosureCallNode(ClosureCallNode* node);
   virtual void VisitStaticSetterNode(StaticSetterNode* node);
   virtual void VisitStoreStaticFieldNode(StoreStaticFieldNode* node);
   virtual void VisitTypeNode(TypeNode* node);
   virtual void VisitLetNode(LetNode* node);
+  virtual void VisitInstanceCallNode(InstanceCallNode* node);
 
   Value* value() const { return value_; }
 
  protected:
   // Output parameters.
   Value* value_;
 
  private:
   // Helper to set the output state to return a Value.
   virtual void ReturnValue(Value* value) { value_ = value; }
@@ skipping 65 matching lines @@
   // Output parameters.
   GrowableArray<TargetEntryInstr**> true_successor_addresses_;
   GrowableArray<TargetEntryInstr**> false_successor_addresses_;
 
   intptr_t condition_token_pos_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_