[turbofan] Properly optimize JSToBoolean with Number inputs.

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 04b9b8cefde22dc5904ab8d3dcb390151c03efeb..78a0687d15a9ebe8cd339f3e9fd7c20f43f99e1b 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -830,6 +830,14 @@ Reduction JSTypedLowering::ReduceJSToBoolean(Node* node) {
     node->TrimInputCount(1);
     NodeProperties::ChangeOp(node, simplified()->BooleanNot());
     return Changed(node);
+  } else if (input_type->Is(Type::Number())) {
+    // JSToBoolean(x:number) => NumberLessThan(#0,NumberAbs(x))
+    RelaxEffectsAndControls(node);
+    node->ReplaceInput(0, jsgraph()->ZeroConstant());
+    node->ReplaceInput(1, graph()->NewNode(simplified()->NumberAbs(), input));
+    node->TrimInputCount(2);
+    NodeProperties::ChangeOp(node, simplified()->NumberLessThan());
+    return Changed(node);
   } else if (input_type->Is(Type::String())) {
     // JSToBoolean(x:string) => NumberLessThan(#0,x.length)
     FieldAccess const access = AccessBuilder::ForStringLength();