[turbofan] Fix tail call optimization.

src/compiler/node.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_NODE_H_
 #define V8_COMPILER_NODE_H_
 
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 #include "src/types-inl.h"
@@ skipping 128 matching lines @@
     Node* node_;
   };
 
   Uses uses() { return Uses(this); }
 
   // Returns true if {owner} is the user of {this} node.
   bool OwnedBy(Node* owner) const {
     return first_use_ && first_use_->from == owner && !first_use_->next;
   }
 
+  // Returns true if {owner1} and {owner2} are the only users of {this} node.
+  bool OwnedBy(Node const* owner1, Node const* owner2) const;
+
  private:
   struct Use final : public ZoneObject {
     Node* from;
     Use* next;
     Use* prev;
     int input_index;
   };
 
   class Input final {
    public:
@@ skipping 317 matching lines @@
 
 void Node::ReplaceInput(int index, Node* new_to) {
   GetInputRecordPtr(index)->Update(new_to);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_NODE_H_