[turbofan] Switch JSForInPrepare to %ForInPrepare style.

src/compiler/js-typed-lowering.h

Index: src/compiler/js-typed-lowering.h
diff --git a/src/compiler/js-typed-lowering.h b/src/compiler/js-typed-lowering.h
index 68ce74e6245396b3501ca0ce48d6ca057be1d32c..fe57716f888c3113f66985acef18fc8617043c31 100644
--- a/src/compiler/js-typed-lowering.h
+++ b/src/compiler/js-typed-lowering.h
@@ -83,7 +83,6 @@ class JSTypedLowering final : public AdvancedReducer {
   Reduction ReduceJSCallFunction(Node* node);
   Reduction ReduceJSForInDone(Node* node);
   Reduction ReduceJSForInNext(Node* node);
-  Reduction ReduceJSForInPrepare(Node* node);
   Reduction ReduceJSForInStep(Node* node);
   Reduction ReduceSelect(Node* node);
   Reduction ReduceNumberBinop(Node* node, const Operator* numberOp);