Remove the ability in dart2js to turn off syntax-only generic methods.

pkg/compiler/lib/src/serialization/resolved_ast_serialization.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 dart2js.serialization.resolved_ast;
 
 import '../common.dart';
 import '../common/resolution.dart';
 import '../constants/expressions.dart';
 import '../dart_types.dart';
@@ skipping 382 matching lines @@
 
     /// Create the [Node] for the element by parsing the source code.
     Node doParse(parse(Parser parser)) {
       return parsing.measure(() {
         return reporter.withCurrentElement(element, () {
           CompilationUnitElement unit = element.compilationUnit;
           NodeListener listener = new NodeListener(
               parsing.getScannerOptionsFor(element), reporter, null);
           listener.memberErrors = listener.memberErrors.prepend(false);
           try {
-            Parser parser = new Parser(listener, parsing.parserOptions);
+            Parser parser = new Parser(listener);
             parse(parser);
           } on ParserError catch (e) {
             reporter.internalError(element, '$e');
           }
           return listener.popNode();
         });
       });
     }
 
     /// Computes the [Node] for the element based on the [AstKind].
@@ skipping 273 matching lines @@
         }
       }
     }
     element.resolvedAst =
         new ParsedResolvedAst(element, root, body, elements, uri);
   }
 }
 
 const Key PARAMETER_NODE = const Key('parameter.node');
 const Key PARAMETER_INITIALIZER = const Key('parameter.initializer');