Emit named parameter information in declaration order.

sdk/lib/_internal/lib/js_helper.dart

Index: sdk/lib/_internal/lib/js_helper.dart
diff --git a/sdk/lib/_internal/lib/js_helper.dart b/sdk/lib/_internal/lib/js_helper.dart
index 9eff25f46695f1ed79d049057af774798aeb6bed..c9134a2e5be9f381bd7feed0f5b62740b84c454c 100644
--- a/sdk/lib/_internal/lib/js_helper.dart
+++ b/sdk/lib/_internal/lib/js_helper.dart
@@ -455,7 +455,7 @@ class ReflectionInfo {
       }
       int index = 0;
       (positions.keys.toList()..sort()).forEach((String name) {
-        cachedSortedIndices[index++] = positions[name] + requiredParameterCount;
+        cachedSortedIndices[index++] = positions[name];
       });
     }
     return cachedSortedIndices[unsortedIndex];