Use message.yaml in parser.

pkg/front_end/test/subpackage_relationships_test.dart

Index: pkg/front_end/test/subpackage_relationships_test.dart
diff --git a/pkg/front_end/test/subpackage_relationships_test.dart b/pkg/front_end/test/subpackage_relationships_test.dart
index 218b65cbed3f42995394ef396718801395ea6fd9..df40d0b1414b2d305814c1c17532584056cc2b2e 100644
--- a/pkg/front_end/test/subpackage_relationships_test.dart
+++ b/pkg/front_end/test/subpackage_relationships_test.dart
@@ -77,7 +77,6 @@ final subpackageRules = {
   ]),
   'lib/src/fasta/scanner': new SubpackageRules(allowedDependencies: [
     'lib/src/fasta',
-    'lib/src/fasta/parser',
     // fasta scanner produces analyzer scanner tokens
     'lib/src/scanner',
     'lib/src/fasta/util',
@@ -102,6 +101,8 @@ final subpackageRules = {
   'lib/src/fasta/util': new SubpackageRules(),
   'lib/src/scanner': new SubpackageRules(allowedDependencies: [
     'lib/src/base',
+    // For error codes.
+    'lib/src/fasta',
     // fasta scanner produces analyzer scanner tokens
     'lib/src/fasta/scanner',
   ]),