[turbofan] compute arguments length in deoptimizer

src/compiler/common-operator.h

Index: src/compiler/common-operator.h
diff --git a/src/compiler/common-operator.h b/src/compiler/common-operator.h
index b823e0fa154df51dd0346d71d18a98e882c7ab87..d54bcc531109bba685b47ceaef3772c94c7647ce 100644
--- a/src/compiler/common-operator.h
+++ b/src/compiler/common-operator.h
@@ -297,9 +297,9 @@ SparseInputMask SparseInputMaskOf(Operator const*);
 ZoneVector<MachineType> const* MachineTypesOf(Operator const*)
     WARN_UNUSED_RESULT;
 
-// The ArgumentsElementsState can either describe an unmapped arguments backing
-// store or the backing store of the rest parameters. IsRestOf(op) is true in
-// the second case.
+// The ArgumentsElementsState and ArgumentsLengthState can either describe an
+// unmapped arguments backing store or the backing store of the rest parameters.
+// IsRestOf(op) is true in the second case.
 bool IsRestOf(Operator const*);
 
 // Interface for building common operators that can be used at any level of IR,
@@ -368,6 +368,7 @@ class V8_EXPORT_PRIVATE CommonOperatorBuilder final
   const Operator* TypedStateValues(const ZoneVector<MachineType>* types,
                                    SparseInputMask bitmask);
   const Operator* ArgumentsElementsState(bool is_rest);
+  const Operator* ArgumentsLengthState(bool is_rest);
   const Operator* ObjectState(int pointer_slots);
   const Operator* TypedObjectState(const ZoneVector<MachineType>* types);
   const Operator* FrameState(BailoutId bailout_id,