dart2js cps: Ensure parameter default values are emitted.

pkg/compiler/lib/src/js_backend/codegen/glue.dart

Index: pkg/compiler/lib/src/js_backend/codegen/glue.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/glue.dart b/pkg/compiler/lib/src/js_backend/codegen/glue.dart
index e6f5909ab90fd8a68643800d7292a4e50f0e61c2..ac91652ee8b8bd781fa244396663fa638b4c42a0 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/glue.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/glue.dart
@@ -65,10 +65,6 @@ class Glue {
     return classWorld.isUsedAsMixin(classElement);
   }
 
-  ConstantValue getConstantValueForVariable(VariableElement variable) {
-    return _backend.constants.getConstantValueForVariable(variable);
-  }
-
   js.Expression staticFunctionAccess(FunctionElement element) {
     return _backend.emitter.staticFunctionAccess(element);
   }
@@ -291,4 +287,8 @@ class Glue {
     if (nativeBehavior == null) return;
     _enqueuer.nativeEnqueuer.registerNativeBehavior(nativeBehavior, node);
   }
+
+  ConstantValue getDefaultParameterValue(ParameterElement elem) {
+    return _backend.constants.getConstantValueForVariable(elem);
+  }
 }