Don't crash on generic methods.

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

 // Copyright (c) 2016, 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 fasta.body_builder;
 
 import '../parser/parser.dart' show FormalParameterType, optional;
 
 import '../parser/error_kind.dart' show ErrorKind;
 
@@ skipping 2145 matching lines @@
           "Can't continue at '$name'.", continueKeyword.next.charOffset));
     } else {
       BreakStatement statement = new BreakStatement(null);
       target.addContinue(statement);
       push(statement);
     }
   }
 
   @override
   void endTypeVariable(Token token, Token extendsOrSuper) {
-    logEvent("TypeVariable");
-    // TODO(ahe): Implement this when enabling generic method syntax.
+    debugEvent("TypeVariable");
+    // TODO(ahe): Do not discard these when enabling generic method syntax.
+    pop(); // Bound.
+    pop(); // Name.
   }
 
   @override
   void endTypeVariables(int count, Token beginToken, Token endToken) {
-    logEvent("TypeVariables");
+    debugEvent("TypeVariables");
     // TODO(ahe): Implement this when enabling generic method syntax.
+    push(NullValue.TypeVariables);
   }
 
   @override
   void handleModifier(Token token) {
     debugEvent("Modifier");
     // TODO(ahe): Copied from outline_builder.dart.
     push(new Modifier.fromString(token.stringValue));
   }
 
   @override
@@ skipping 523 matching lines @@
   } else if (node is PrefixBuilder) {
     return node.name;
   } else if (node is ThisAccessor) {
     return node.isSuper ? "super" : "this";
   } else if (node is BuilderAccessor) {
     return node.plainNameForRead;
   } else {
     return internalError("Unhandled: ${node.runtimeType}");
   }
 }