Tighter native type annotations for some elements returning Lists

sdk/lib/_internal/lib/js_rti.dart

Index: sdk/lib/_internal/lib/js_rti.dart
diff --git a/sdk/lib/_internal/lib/js_rti.dart b/sdk/lib/_internal/lib/js_rti.dart
index 432d2374021223ec4d8a611d91f38e4249691c72..ea01f76a141ffb51eb8d921530cba714d200566d 100644
--- a/sdk/lib/_internal/lib/js_rti.dart
+++ b/sdk/lib/_internal/lib/js_rti.dart
@@ -418,7 +418,7 @@ bool checkSubtypeOfRuntimeType(Object o, var t) {
     // If the type has type variables (that is, [:rti != null:]), make a copy of
     // the type arguments and insert [o] in the first position to create a
     // compound type representation.
-    type = JS('List', '#.slice()', rti);
+    type = JS('JSExtendableArray', '#.slice()', rti);
     JS('', '#.splice(0, 0, #)', type, o);
   } else {
     // Use the object as representation of the raw type.