[crankshaft] Remove the useless HMapEnumLength instruction.

src/crankshaft/hydrogen-instructions.cc

 // Copyright 2012 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.
 
 #include "src/crankshaft/hydrogen-instructions.h"
 
 #include "src/base/bits.h"
 #include "src/base/safe_math.h"
 #include "src/crankshaft/hydrogen-infer-representation.h"
 #include "src/double.h"
@@ skipping 793 matching lines @@
     case HValue::kInstanceOf:
     case HValue::kIsSmiAndBranch:
     case HValue::kIsStringAndBranch:
     case HValue::kIsUndetectableAndBranch:
     case HValue::kLeaveInlined:
     case HValue::kLoadFieldByIndex:
     case HValue::kLoadGlobalGeneric:
     case HValue::kLoadNamedField:
     case HValue::kLoadNamedGeneric:
     case HValue::kLoadRoot:
-    case HValue::kMapEnumLength:
     case HValue::kMathMinMax:
     case HValue::kParameter:
     case HValue::kPhi:
     case HValue::kPushArguments:
     case HValue::kReturn:
     case HValue::kSeqStringGetChar:
     case HValue::kStoreCodeEntry:
     case HValue::kStoreFrameContext:
     case HValue::kStoreKeyed:
     case HValue::kStoreNamedField:
@@ skipping 3868 matching lines @@
     case HObjectAccess::kExternalMemory:
       os << "[external-memory]";
       break;
   }
 
   return os << "@" << access.offset();
 }
 
 }  // namespace internal
 }  // namespace v8