[crankshaft] Remove the useless HMapEnumLength instruction.

src/crankshaft/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 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/arm64/lithium-codegen-arm64.h"
 
 #include "src/arm64/frames-arm64.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 3387 matching lines @@
   DCHECK(ToRegister(instr->result()).is(x0));
 }
 
 
 void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
   Register result = ToRegister(instr->result());
   __ LoadRoot(result, instr->index());
 }
 
 
-void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
-  Register result = ToRegister(instr->result());
-  Register map = ToRegister(instr->value());
-  __ EnumLengthSmi(result, map);
-}
-
-
 void LCodeGen::DoMathAbs(LMathAbs* instr) {
   Representation r = instr->hydrogen()->value()->representation();
   if (r.IsDouble()) {
     DoubleRegister input = ToDoubleRegister(instr->value());
     DoubleRegister result = ToDoubleRegister(instr->result());
     __ Fabs(result, input);
   } else if (r.IsSmi() || r.IsInteger32()) {
     Register input = r.IsSmi() ? ToRegister(instr->value())
                                : ToRegister32(instr->value());
     Register result = r.IsSmi() ? ToRegister(instr->result())
@@ skipping 2342 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 }  // namespace internal
 }  // namespace v8