[turbofan] Add and use bytecode loop assigment analysis

src/interpreter/bytecode-array-accessor.h

 // Copyright 2016 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_INTERPRETER_BYTECODE_ARRAY_ACCESSOR_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_ACCESSOR_H_
 
 #include "src/globals.h"
 #include "src/handles.h"
 #include "src/interpreter/bytecode-register.h"
@@ skipping 30 matching lines @@
   int GetRegisterOperandRange(int operand_index) const;
   Runtime::FunctionId GetRuntimeIdOperand(int operand_index) const;
   Runtime::FunctionId GetIntrinsicIdOperand(int operand_index) const;
   Handle<Object> GetConstantForIndexOperand(int operand_index) const;
 
   // Returns the absolute offset of the branch target at the current
   // bytecode. It is an error to call this method if the bytecode is
   // not for a jump or conditional jump.
   int GetJumpTargetOffset() const;
 
+  bool OffsetWithinBytecode(int offset) const;
+
   std::ostream& PrintTo(std::ostream& os) const;
 
  private:
   bool OffsetInBounds() const;
 
   uint32_t GetUnsignedOperand(int operand_index,
                               OperandType operand_type) const;
   int32_t GetSignedOperand(int operand_index, OperandType operand_type) const;
 
   void UpdateOperandScale();
 
   Handle<BytecodeArray> bytecode_array_;
   int bytecode_offset_;
   OperandScale operand_scale_;
   int prefix_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeArrayAccessor);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_GRAPH_ACCESSOR_H_