[builtins] Migrate Math.clz32 to a TurboFan builtin.

src/compiler/js-intrinsic-lowering.cc

 // Copyright 2015 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/js-intrinsic-lowering.h"
 
 #include <stack>
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
@@ skipping 32 matching lines @@
     case Runtime::kInlineIsArray:
       return ReduceIsInstanceType(node, JS_ARRAY_TYPE);
     case Runtime::kInlineIsTypedArray:
       return ReduceIsInstanceType(node, JS_TYPED_ARRAY_TYPE);
     case Runtime::kInlineIsRegExp:
       return ReduceIsInstanceType(node, JS_REGEXP_TYPE);
     case Runtime::kInlineIsJSReceiver:
       return ReduceIsJSReceiver(node);
     case Runtime::kInlineIsSmi:
       return ReduceIsSmi(node);
-    case Runtime::kInlineMathClz32:
-      return ReduceMathClz32(node);
     case Runtime::kInlineValueOf:
       return ReduceValueOf(node);
     case Runtime::kInlineFixedArrayGet:
       return ReduceFixedArrayGet(node);
     case Runtime::kInlineFixedArraySet:
       return ReduceFixedArraySet(node);
     case Runtime::kInlineRegExpConstructResult:
       return ReduceRegExpConstructResult(node);
     case Runtime::kInlineRegExpExec:
       return ReduceRegExpExec(node);
@@ skipping 132 matching lines @@
 Reduction JSIntrinsicLowering::ReduceIsJSReceiver(Node* node) {
   return Change(node, simplified()->ObjectIsReceiver());
 }
 
 
 Reduction JSIntrinsicLowering::ReduceIsSmi(Node* node) {
   return Change(node, simplified()->ObjectIsSmi());
 }
 
 
-Reduction JSIntrinsicLowering::ReduceMathClz32(Node* node) {
-  return Change(node, machine()->Word32Clz());
-}
-
-
 Reduction JSIntrinsicLowering::ReduceValueOf(Node* node) {
   // if (%_IsSmi(value)) {
   //   return value;
   // } else if (%_GetInstanceType(%_GetMap(value)) == JS_VALUE_TYPE) {
   //   return %_GetValue(value);
   // } else {
   //   return value;
   // }
   const Operator* const merge_op = common()->Merge(2);
   const Operator* const ephi_op = common()->EffectPhi(2);
@@ skipping 276 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSIntrinsicLowering::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8