Issue 22988. Improve checking for conflicts between parameters and local elements during extracting…

pkg/analysis_server/test/mock_sdk.dart

Index: pkg/analysis_server/test/mock_sdk.dart
diff --git a/pkg/analysis_server/test/mock_sdk.dart b/pkg/analysis_server/test/mock_sdk.dart
index 920cb32f36c048ca9cedcd0a855d5d3bd1458cdd..abc6a3c05bdada3f50499c4e367f6ecde7383906 100644
--- a/pkg/analysis_server/test/mock_sdk.dart
+++ b/pkg/analysis_server/test/mock_sdk.dart
@@ -51,6 +51,7 @@ abstract class num implements Comparable<num> {
   num operator +(num other);
   num operator -(num other);
   num operator *(num other);
+  num operator %(num other);
   num operator /(num other);
   int toInt();
   num abs();