[crankshaft] Remove the useless HMapEnumLength instruction.

src/crankshaft/mips64/lithium-mips64.h

 // 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.
 
 #ifndef V8_CRANKSHAFT_MIPS64_LITHIUM_MIPS_H_
 #define V8_CRANKSHAFT_MIPS64_LITHIUM_MIPS_H_
 
 #include "src/crankshaft/hydrogen.h"
 #include "src/crankshaft/lithium.h"
 #include "src/crankshaft/lithium-allocator.h"
@@ skipping 85 matching lines @@
   V(LazyBailout)                             \
   V(LoadContextSlot)                         \
   V(LoadRoot)                                \
   V(LoadFieldByIndex)                        \
   V(LoadFunctionPrototype)                   \
   V(LoadGlobalGeneric)                       \
   V(LoadKeyed)                               \
   V(LoadKeyedGeneric)                        \
   V(LoadNamedField)                          \
   V(LoadNamedGeneric)                        \
-  V(MapEnumLength)                           \
   V(MathAbs)                                 \
   V(MathExp)                                 \
   V(MathClz32)                               \
   V(MathFloor)                               \
   V(MathFround)                              \
   V(MathLog)                                 \
   V(MathMinMax)                              \
   V(MathPowHalf)                             \
   V(MathRound)                               \
   V(MathSqrt)                                \
@@ skipping 1232 matching lines @@
   LOperand* value() { return inputs_[0]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(CmpMapAndBranch, "cmp-map-and-branch")
   DECLARE_HYDROGEN_ACCESSOR(CompareMap)
 
   Handle<Map> map() const { return hydrogen()->map().handle(); }
 };
 
 
-class LMapEnumLength final : public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LMapEnumLength(LOperand* value) {
-    inputs_[0] = value;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(MapEnumLength, "map-enum-length")
-};
-
-
 class LSeqStringGetChar final : public LTemplateInstruction<1, 2, 0> {
  public:
   LSeqStringGetChar(LOperand* string, LOperand* index) {
     inputs_[0] = string;
     inputs_[1] = index;
   }
 
   LOperand* string() const { return inputs_[0]; }
   LOperand* index() const { return inputs_[1]; }
 
@@ skipping 1402 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CRANKSHAFT_MIPS64_LITHIUM_MIPS_H_