[turbofan] Add RegisterAllocator::NewLiveRange() utility method.

src/compiler/register-allocator.h

 // Copyright 2014 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_REGISTER_ALLOCATOR_H_
 #define V8_REGISTER_ALLOCATOR_H_
 
 #include "src/compiler/instruction.h"
 #include "src/zone-containers.h"
 
@@ skipping 452 matching lines @@
  private:
   int GetVirtualRegister() { return code()->NextVirtualRegister(); }
 
   // Checks whether the value of a given virtual register is a reference.
   // TODO(titzer): rename this to IsReference.
   bool HasTaggedValue(int virtual_register) const;
 
   // Returns the register kind required by the given virtual register.
   RegisterKind RequiredRegisterKind(int virtual_register) const;
 
+  // Creates a new live range.
+  LiveRange* NewLiveRange(int index);
+
   // This zone is for InstructionOperands and moves that live beyond register
   // allocation.
   Zone* code_zone() const { return code()->zone(); }
 
   BitVector* assigned_registers() { return assigned_registers_; }
   BitVector* assigned_double_registers() { return assigned_double_registers_; }
 
 #ifdef DEBUG
   void Verify() const;
 #endif
@@ skipping 171 matching lines @@
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(RegisterAllocator);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGISTER_ALLOCATOR_H_