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

src/compiler/js-intrinsic-lowering.cc

Index: src/compiler/js-intrinsic-lowering.cc
diff --git a/src/compiler/js-intrinsic-lowering.cc b/src/compiler/js-intrinsic-lowering.cc
index 6bc1c46672307011aeba3bda367ce1fd4279fc6c..b2bd54db409813dd63dd51152e070555478abb77 100644
--- a/src/compiler/js-intrinsic-lowering.cc
+++ b/src/compiler/js-intrinsic-lowering.cc
@@ -50,8 +50,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceIsJSReceiver(node);
     case Runtime::kInlineIsSmi:
       return ReduceIsSmi(node);
-    case Runtime::kInlineMathClz32:
-      return ReduceMathClz32(node);
     case Runtime::kInlineValueOf:
       return ReduceValueOf(node);
     case Runtime::kInlineFixedArrayGet:
@@ -204,11 +202,6 @@ Reduction JSIntrinsicLowering::ReduceIsSmi(Node* node) {
 }
 
 
-Reduction JSIntrinsicLowering::ReduceMathClz32(Node* node) {
-  return Change(node, machine()->Word32Clz());
-}
-
-
 Reduction JSIntrinsicLowering::ReduceValueOf(Node* node) {
   // if (%_IsSmi(value)) {
   //   return value;