[turbofan] Turn Math.clz32 into an inlinable builtin.

src/compiler/arm64/code-generator-arm64.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/compiler/code-generator.h"
 
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 613 matching lines @@
       // TODO(dcarney): test slot offset and register order.
       int slot = MiscField::decode(instr->opcode()) - 1;
       __ PokePair(i.InputRegister(0), xzr, slot * kPointerSize);
       break;
     }
     case kArm64PokePair: {
       int slot = MiscField::decode(instr->opcode()) - 1;
       __ PokePair(i.InputRegister(1), i.InputRegister(0), slot * kPointerSize);
       break;
     }
+    case kArm64Clz32:
+      __ Clz(i.OutputRegister32(), i.InputRegister32(0));
+      break;
     case kArm64Cmp:
       __ Cmp(i.InputRegister(0), i.InputOperand(1));
       break;
     case kArm64Cmp32:
       __ Cmp(i.InputRegister32(0), i.InputOperand32(1));
       break;
     case kArm64Cmn:
       __ Cmn(i.InputRegister(0), i.InputOperand(1));
       break;
     case kArm64Cmn32:
@@ skipping 562 matching lines @@
     }
   }
   MarkLazyDeoptSite();
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8