Add the --build-summary-exclude-informative flag.

pkg/analyzer/tool/summary/idl_model.dart

Index: pkg/analyzer/tool/summary/idl_model.dart
diff --git a/pkg/analyzer/tool/summary/idl_model.dart b/pkg/analyzer/tool/summary/idl_model.dart
index 9ec248f994e41695ad4749531a100f0946ad8101..18b981cb57433bf3fa19e41472f65eac0dc8884b 100644
--- a/pkg/analyzer/tool/summary/idl_model.dart
+++ b/pkg/analyzer/tool/summary/idl_model.dart
@@ -25,7 +25,7 @@ class ClassDeclaration extends Declaration {
 
   /**
    * If [isTopLevel] is `true` and a file identifier was specified for this
-   * class, the file identifier string.  Otheswise `null`.
+   * class, the file identifier string.  Otherwise `null`.
    */
   final String fileIdentifier;
 
@@ -97,8 +97,13 @@ class FieldDeclaration extends Declaration {
    */
   final bool isDeprecated;
 
-  FieldDeclaration(
-      String documentation, String name, this.type, this.id, this.isDeprecated)
+  /**
+   * Indicates whether the field is informative.
+   */
+  final bool isInformative;
+
+  FieldDeclaration(String documentation, String name, this.type, this.id,
+      this.isDeprecated, this.isInformative)
       : super(documentation, name);
 }