Limit hints on empty hide on package imports.

pkg/compiler/lib/src/diagnostics/diagnostic_listener.dart

Index: pkg/compiler/lib/src/diagnostics/diagnostic_listener.dart
diff --git a/pkg/compiler/lib/src/diagnostics/diagnostic_listener.dart b/pkg/compiler/lib/src/diagnostics/diagnostic_listener.dart
index cfef59fbabd60edc3dcea1d0f2ffa2ba28f3a8cc..7d624b234a7c3e0f3b27a06797f35a05b0a5a9f0 100644
--- a/pkg/compiler/lib/src/diagnostics/diagnostic_listener.dart
+++ b/pkg/compiler/lib/src/diagnostics/diagnostic_listener.dart
@@ -13,12 +13,26 @@ import '../elements/elements.dart' show
 import 'messages.dart';
 
 class DiagnosticOptions {
-  final bool suppressWarnings;
+
+  /// Emit terse diagnostics without howToFix.
   final bool terseDiagnostics;
+
+  /// If `true`, warnings and hints not from user code are reported.
   final bool showPackageWarnings;
 
+  /// If `true`, warnings are not reported.
+  final bool suppressWarnings;
+
+  /// If `true`, warnings cause the compilation to fail.
+  final bool fatalWarnings;
+
+  /// If `true`, hints are not reported.
+  final bool suppressHints;
+
   const DiagnosticOptions({
     this.suppressWarnings: false,
+    this.fatalWarnings: false,
+    this.suppressHints: false,
     this.terseDiagnostics: false,
     this.showPackageWarnings: false});
 }