Fixed tests so they do indeed confirm that values on optional named parameters are not allowed. Add…

lib/compiler/implementation/scanner/parser.dart

Index: lib/compiler/implementation/scanner/parser.dart
diff --git a/lib/compiler/implementation/scanner/parser.dart b/lib/compiler/implementation/scanner/parser.dart
index 16ef40061de8c2bbd6d0cb76ca5a39028e9efacf..03c6c4e19b9307cd6df49c8040d0bfc5c047bd2d 100644
--- a/lib/compiler/implementation/scanner/parser.dart
+++ b/lib/compiler/implementation/scanner/parser.dart
@@ -69,7 +69,7 @@ class Parser {
     token = parseReturnTypeOpt(token.next);
     token = parseIdentifier(token);
     token = parseTypeVariablesOpt(token);
-    token = parseFormalParameters(token);
+    token = parseFormalParameters(token, DISALLOW_VALUES_FOR_NAMED_OPTIONAL_PARAMS);
     listener.endFunctionTypeAlias(typedefKeyword, token);
     return expect(';', token);
   }
@@ -83,7 +83,8 @@ class Parser {
     }
   }
 
-  Token parseFormalParameters(Token token) {
+  final bool DISALLOW_VALUES_FOR_NAMED_OPTIONAL_PARAMS = false;
+  Token parseFormalParameters(Token token, [bool allowValuesForNamedOptionalParams = true]) {
     Token begin = token;
     listener.beginFormalParameters(begin);
     expect('(', token);
@@ -96,16 +97,16 @@ class Parser {
       ++parameterCount;
       token = token.next;
       if (optional('[', token)) {
-        token = parseOptionalFormalParameters(token);
+        token = parseOptionalFormalParameters(token, allowValuesForNamedOptionalParams);
         break;
       }
-      token = parseFormalParameter(token);
+      token = parseFormalParameter(token, allowValuesForNamedOptionalParams);
     } while (optional(',', token));
     listener.endFormalParameters(parameterCount, begin, token);
     return expect(')', token);
   }
 
-  Token parseFormalParameter(Token token) {
+  Token parseFormalParameter(Token token, bool allowValuesForNamedOptionalParams) {
     listener.beginFormalParameter(token);
     token = parseModifiers(token);
     // TODO(ahe): Validate that there are formal parameters if void.
@@ -119,10 +120,14 @@ class Parser {
     }
     token = parseIdentifier(token);
     if (optional('(', token)) {
-      token = parseFormalParameters(token);
+      token = parseFormalParameters(token, DISALLOW_VALUES_FOR_NAMED_OPTIONAL_PARAMS);
       listener.handleFunctionTypedFormalParameter(token);
     }
     if (optional('=', token)) {
+      if (!allowValuesForNamedOptionalParams) {
+        listener.recoverableError("parameter must not specify a default value", token: token);
+      }
+
       // TODO(ahe): Validate that these are only used for optional parameters.
       Token equal = token;
       token = parseExpression(token.next);
@@ -132,14 +137,14 @@ class Parser {
     return token;
   }
 
-  Token parseOptionalFormalParameters(Token token) {
+  Token parseOptionalFormalParameters(Token token, bool allowValuesForNamedOptionalParams) {
     Token begin = token;
     listener.beginOptionalFormalParameters(begin);
     assert(optional('[', token));
     int parameterCount = 0;
     do {
       token = token.next;
-      token = parseFormalParameter(token);
+      token = parseFormalParameter(token, allowValuesForNamedOptionalParams);
       ++parameterCount;
     } while (optional(',', token));
     listener.endOptionalFormalParameters(parameterCount, begin, token);