Implement generalized function types.

pkg/front_end/lib/src/fasta/parser/identifier_context.dart

Index: pkg/front_end/lib/src/fasta/parser/identifier_context.dart
diff --git a/pkg/front_end/lib/src/fasta/parser/identifier_context.dart b/pkg/front_end/lib/src/fasta/parser/identifier_context.dart
index 29152efd84dcf56bf1278b91ce866b4f81fc2639..5908d9285d4823531609f01626fdf93a3f872272 100644
--- a/pkg/front_end/lib/src/fasta/parser/identifier_context.dart
+++ b/pkg/front_end/lib/src/fasta/parser/identifier_context.dart
@@ -113,6 +113,12 @@ class IdentifierContext {
       inDeclaration: true,
       isBuiltInIdentifierAllowed: false);
 
+  /// Identifier is the start of a reference to a type that starts with prefix.
+  static const prefixedTypeReference = const IdentifierContext._(
+      'prefixedTypeReference',
+      isScopeReference: true,
+      isBuiltInIdentifierAllowed: true);
+
   /// Identifier is the start of a reference to a type declared elsewhere.
   static const typeReference = const IdentifierContext._('typeReference',
       isScopeReference: true, isBuiltInIdentifierAllowed: false);