Emit a compile-time error when using default values in function typed parameter.

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

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart2js;
 
 const DONT_KNOW_HOW_TO_FIX = "";
 
 /**
  * The messages in this file should meet the following guide lines:
@@ skipping 569 matching lines @@
       howToFix: "Try replacing ':' with '='.",
       examples: const ["""
 main() {
   foo([a: 1]) => print(a);
   foo(2);
 }"""]);
 
   static const MessageKind TYPEDEF_FORMAL_WITH_DEFAULT = const MessageKind(
       "Error: A parameter of a typedef can't specify a default value.",
       howToFix:
-        "Try removing the default value or making the parameter optional.",
+        "Try removing the default value.",
       examples: const ["""
 typedef void F([int arg = 0]);
 
 main() {
   F f;
 }""", """
 typedef void F({int arg: 0});
 
 main() {
   F f;
 }"""]);
 
+  static const MessageKind FUNCTION_TYPE_FORMAL_WITH_DEFAULT = const MessageKind(
+      "Error: A function type parameters can't specify a default value.",
+      howToFix:
+        "Try removing the default value.",
+      examples: const ["""
+foo(void f(int i, [a = 1]) {}
+
+main() {
+  foo(1, 2);
+}""", """
+foo(void f(int i, {a: 1}) {}
+
+main() {
+  foo(1, a: 2);
+}"""]);
+
   static const MessageKind FORMAL_DECLARED_CONST = const MessageKind(
       "Error: A formal parameter can't be declared const.",
       howToFix: "Try removing 'const'.",
       examples: const ["""
 foo(const x) {}
 main() => foo(42);
 """, """
 foo({const x}) {}
 main() => foo(42);
 """, """
@@ skipping 817 matching lines @@
 
 class CompileTimeConstantError extends Diagnostic {
   CompileTimeConstantError(MessageKind kind, Map arguments, bool terse)
     : super(kind, arguments, terse);
 }
 
 class CompilationError extends Diagnostic {
   CompilationError(MessageKind kind, Map arguments, bool terse)
     : super(kind, arguments, terse);
 }