[turbofan] Don't introduce PlainPrimitiveToNumber for String 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 7abbbd5190a9c8f28bef38dd6caa38fc0db7af61..46bf61b45796a69e9125bf962e985fa47f2fd777 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -525,7 +525,7 @@ Reduction JSTypedLowering::ReduceNumberBinop(Node* node) {
   NumberOperationHint hint;
   if (r.GetBinaryNumberOperationHint(&hint)) {
     if (hint == NumberOperationHint::kNumberOrOddball &&
-        r.BothInputsAre(Type::PlainPrimitive())) {
+        r.BothInputsAre(Type::NumberOrOddball())) {
       r.ConvertInputsToNumber();
       return r.ChangeToPureOperator(r.NumberOp(), Type::Number());
     }