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

pkg/compiler/lib/src/parser/partial_elements.dart

Index: pkg/compiler/lib/src/parser/partial_elements.dart
diff --git a/pkg/compiler/lib/src/parser/partial_elements.dart b/pkg/compiler/lib/src/parser/partial_elements.dart
index 87cb2f152c42f956f62334da42fe2eff2182dc79..1f37ff3d2e7b4e8c06b07418189b95cbac78ca63 100644
--- a/pkg/compiler/lib/src/parser/partial_elements.dart
+++ b/pkg/compiler/lib/src/parser/partial_elements.dart
@@ -374,7 +374,7 @@ class PartialClassElement extends ClassElementX with PartialElement {
       parsing.measure(() {
         MemberListener listener = new MemberListener(
             parsing.getScannerOptionsFor(this), reporter, this);
-        Parser parser = new ClassElementParser(listener, parsing.parserOptions);
+        Parser parser = new ClassElementParser(listener);
         try {
           Token token = parser.parseTopLevelDeclaration(beginToken);
           assert(identical(token, endToken.next));
@@ -440,7 +440,7 @@ Node parse(ParsingContext parsing, ElementX element, PartialElement partial,
         if (partial.hasParseError) {
           listener.suppressParseErrors = true;
         }
-        doParse(new Parser(listener, parsing.parserOptions));
+        doParse(new Parser(listener));
       } on ParserError catch (e) {
         partial.hasParseError = true;
         return new ErrorNode(element.position, e.reason);