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

src/compiler/simplified-lowering.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/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 921 matching lines @@
       case IrOpcode::kWord32Xor:
       case IrOpcode::kWord32Shl:
       case IrOpcode::kWord32Sar:
         // We use signed int32 as the output type for these word32 operations,
         // though the machine bits are the same for either signed or unsigned,
         // because JavaScript considers the result from these operations signed.
         return VisitBinop(node, kRepWord32, kRepWord32 | kTypeInt32);
       case IrOpcode::kWord32Equal:
         return VisitBinop(node, kRepWord32, kRepBit);
 
+      case IrOpcode::kWord32Clz:
+        return VisitUnop(node, kMachUint32, kMachUint32);
+
       case IrOpcode::kInt32Add:
       case IrOpcode::kInt32Sub:
       case IrOpcode::kInt32Mul:
       case IrOpcode::kInt32MulHigh:
       case IrOpcode::kInt32Div:
       case IrOpcode::kInt32Mod:
         return VisitInt32Binop(node);
       case IrOpcode::kUint32Div:
       case IrOpcode::kUint32Mod:
       case IrOpcode::kUint32MulHigh:
@@ skipping 640 matching lines @@
 
 void SimplifiedLowering::DoStringLessThanOrEqual(Node* node) {
   node->set_op(machine()->IntLessThanOrEqual());
   node->ReplaceInput(0, StringComparison(node, true));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8