Revert "dart2js cps: Handle optional parameters in builder."

pkg/compiler/lib/src/cps_ir/cps_ir_builder.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_builder.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_builder.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_builder.dart
index 61a3b529acc6c4f969bb23781a2c40fe76b90f05..f883b9b9c38613e28b17b3cb0461338efe93a294 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_builder.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_builder.dart
@@ -731,6 +731,14 @@ abstract class IrBuilder {
         (k) => new ir.ConcatenateStrings(k, arguments));
   }
 
+  /// Create an invocation of [local] where the argument structure is defined
+  /// by [selector] and the argument values are defined by [arguments].
+  ir.Primitive buildLocalInvocation(LocalElement local,
+                                    Selector selector,
+                                    List<ir.Definition> arguments) {
+    return _buildInvokeCall(buildLocalGet(local), selector, arguments);
+  }
+
   /// Create an invocation of the [functionExpression] where the argument
   /// structure are defined by [selector] and the argument values are defined by
   /// [arguments].