Emit error on default values in typedefs.

sdk/lib/_internal/compiler/implementation/warnings.dart

Index: sdk/lib/_internal/compiler/implementation/warnings.dart
diff --git a/sdk/lib/_internal/compiler/implementation/warnings.dart b/sdk/lib/_internal/compiler/implementation/warnings.dart
index c108cf83ab36a965fee6166061a65fefb4c3a005..9975fb64a35cb43b0cf386ae78553c7874bdd75e 100644
--- a/sdk/lib/_internal/compiler/implementation/warnings.dart
+++ b/sdk/lib/_internal/compiler/implementation/warnings.dart
@@ -418,6 +418,16 @@ main() => new C(0);"""]);
   static const MessageKind CANNOT_INSTANTIATE_TYPEDEF = const MessageKind(
       'Error: Cannot instantiate typedef "#{typedefName}".');
 
+  static const MessageKind TYPEDEF_FORMAL_WITH_DEFAULT = const MessageKind(
+      "Error: A parameter of a typedef can't specify a default value.",
+      howToFix: "Remove the default value.",
+      examples: const ["""
+typedef void F([int arg: 0]);

[Johnni Winther, 2013/09/09 13:23:18]

Wrong syntax: It should [int arg = 0] or {int arg: 0}. Maybe include both
examples.

[karlklose, 2013/09/09 13:38:56]

Done.

+
+main() {
+  F f;
+}"""]);
+
   static const MessageKind CANNOT_INSTANTIATE_TYPE_VARIABLE = const MessageKind(
       'Error: Cannot instantiate type variable "#{typeVariableName}".');