[turbofan] Unify BooleanToNumber, StringToNumber and PlainPrimitiveToNumber.

src/compiler/js-typed-lowering.cc

Index: src/compiler/js-typed-lowering.cc
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index 985a31e7db80b671b21c80ca9b4fc884266c9fbc..ca88eb49f3590be9f637cd858021c5e12b1a93c7 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -928,14 +928,6 @@ Reduction JSTypedLowering::ReduceJSToNumberInput(Node* input) {
     // JSToNumber(null) => #0
     return Replace(jsgraph()->ZeroConstant());
   }
-  if (input_type->Is(Type::Boolean())) {
-    // JSToNumber(x:boolean) => BooleanToNumber(x)
-    return Replace(graph()->NewNode(simplified()->BooleanToNumber(), input));
-  }
-  if (input_type->Is(Type::String())) {
-    // JSToNumber(x:string) => StringToNumber(x)
-    return Replace(graph()->NewNode(simplified()->StringToNumber(), input));
-  }
   return NoChange();
 }