add for() keyword suggestion

pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart

Index: pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart b/pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart
index 99c9ce31bd3fbde43a4d5736b9917fb5f9a31ca3..33dfa582edeafd2d34cab6c3e9cdd7616e9da28f 100644
--- a/pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart
+++ b/pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart
@@ -375,7 +375,7 @@ class _KeywordVisitor extends GeneralizingAstVisitor {
       Keyword.CONTINUE,
       Keyword.DO,
       Keyword.FINAL,
-      Keyword.FOR,
+      //Keyword.FOR,
       Keyword.IF,
       Keyword.NEW,
       Keyword.RETURN,
@@ -386,6 +386,7 @@ class _KeywordVisitor extends GeneralizingAstVisitor {
       Keyword.VOID,
       Keyword.WHILE
     ]);
+    _addSuggestion2('for ()', offset: 5);
     _addSuggestion(Keyword.RETHROW, DART_RELEVANCE_KEYWORD - 1);
   }