Introduce simplified BooleanToNumber operator.

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 35283e4137402386a71413ee8ca72965e1852531..74849af8a8734bffa39eca783b3c39f2ef2a5209 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -444,7 +444,11 @@ Reduction JSTypedLowering::ReduceJSToNumberInput(Node* input) {
     // JSToNumber(null) => #0
     return ReplaceWith(jsgraph()->ZeroConstant());
   }
-  // TODO(turbofan): js-typed-lowering of ToNumber(x:boolean)
+  if (input_type->Is(Type::Boolean())) {
+    // JSToNumber(x:boolean) => BooleanToNumber(x)
+    return ReplaceWith(
+        graph()->NewNode(simplified()->BooleanToNumber(), input));
+  }
   // TODO(turbofan): js-typed-lowering of ToNumber(x:string)
   return NoChange();
 }