Add TypeVariable object on runtime to support reflection on type variables.

sdk/lib/_internal/lib/js_rti.dart

 // Copyright (c) 2013, 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.
 
 /**
  * This part contains helpers for supporting runtime type information.
  *
  * The helper use a mixture of Dart and JavaScript objects. To indicate which is
  * used where we adopt the scheme of using explicit type annotation for Dart
  * objects and 'var' or omitted return type for JavaScript objects.
@@ skipping 48 matching lines @@
   }
 
   // TODO(ahe): This is a poor hashCode as it collides with its name.
   int get hashCode => _typeName.hashCode;
 
   bool operator ==(other) {
     return  (other is TypeImpl) && _typeName == other._typeName;
   }
 }
 
+/**
+ * Represents a type variable.
+ *
+ * This class holds the information needed when reflecting on generic classes
+ * and their members.
+ */
+class TypeVariable {
+  final Type owner;
+  final String name;
+  final int bound;
+
+  const TypeVariable(this.owner, this.name, this.bound);
+}
+
 getMangledTypeName(TypeImpl type) => type._typeName;
 
 /**
  * Sets the runtime type information on [target]. [typeInfo] is a type
  * representation of type 4 or 5, that is, either a JavaScript array or
  * [:null:].
  */
 Object setRuntimeTypeInfo(Object target, var typeInfo) {
   assert(isNull(typeInfo) || isJsArray(typeInfo));
   // We have to check for null because factories may return null.
@@ skipping 638 matching lines @@
  * and [t] are Dart values.
  */
 bool isIdentical(var s, var t) => JS('bool', '# === #', s, t);
 
 /**
  * Returns [:true:] if the JavaScript values [s] and [t] are not identical. We
  * use this helper to avoid generating code under the invalid assumption that
  * [s] and [t] are Dart values.
  */
 bool isNotIdentical(var s, var t) => JS('bool', '# !== #', s, t);