Fix rti encoding of generic methods

pkg/compiler/lib/src/dart_types.dart

 // Copyright (c) 2012, 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.
 
 library dart_types;
 
 import 'dart:math' show min;
 
 import 'common/resolution.dart' show Resolution;
 import 'common.dart';
@@ skipping 1416 matching lines @@
     });
     // Use the new List only if necessary.
     return changed ? result : types;
   }
 
   /**
    * Returns the [ClassElement] which declares the type variables occurring in
    * [type], or [:null:] if [type] does not contain type variables.
    */
   static ClassElement getClassContext(DartType type) {
-    TypeVariableType typeVariable = type.typeVariableOccurrence;
-    if (typeVariable == null) return null;
+    ClassElement contextClass;
+    type.forEachTypeVariable((TypeVariableType typeVariable) {
+      if (typeVariable.element.typeDeclaration is! ClassElement) return;
+      contextClass = typeVariable.element.typeDeclaration;
+    });
     // GENERIC_METHODS: When generic method support is complete enough to
     // include a runtime value for method type variables this must be updated.
     // For full support the global assumption that all type variables are
     // declared by the same enclosing class will not hold: Both an enclosing
     // method and an enclosing class may define type variables, so the return
     // type cannot be [ClassElement] and the caller must be prepared to look in
     // two locations, not one. Currently we ignore method type variables by
     // returning in the next statement.
-    if (typeVariable.element.typeDeclaration is! ClassElement) return null;
-    return typeVariable.element.typeDeclaration;
+    return contextClass;
   }
 
   /**
    * A `compareTo` function that globally orders types using
    * [Elements.compareByPosition] to order types defined by a declaration.
    *
    * The order is:
    * * void
    * * dynamic
    * * interface, typedef, type variables ordered by element order
@@ skipping 560 matching lines @@
           sb.write(', ');
         }
         namedParameterTypes[index].accept(this, namedParameters[index]);
         needsComma = true;
       }
       sb.write('}');
     }
     sb.write(')');
   }
 }