[arm][arm64] Improve CountTrailingZero implementation.

src/compiler/mips/instruction-selector-mips.cc

 // Copyright 2014 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/base/adapters.h"
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 383 matching lines @@
 void InstructionSelector::VisitWord32Ror(Node* node) {
   VisitRRO(this, kMipsRor, node);
 }
 
 
 void InstructionSelector::VisitWord32Clz(Node* node) {
   VisitRR(this, kMipsClz, node);
 }
 
 
+void InstructionSelector::VisitWord32ReverseBits(Node* node) { UNREACHABLE(); }
+
+
 void InstructionSelector::VisitWord32Ctz(Node* node) {
   MipsOperandGenerator g(this);
   Emit(kMipsCtz, g.DefineAsRegister(node), g.UseRegister(node->InputAt(0)));
 }
 
 
 void InstructionSelector::VisitWord32Popcnt(Node* node) {
   MipsOperandGenerator g(this);
   Emit(kMipsPopcnt, g.DefineAsRegister(node), g.UseRegister(node->InputAt(0)));
 }
@@ skipping 941 matching lines @@
          MachineOperatorBuilder::kFloat32Max |
          MachineOperatorBuilder::kFloat32RoundDown |
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat32RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8