Implement new optional parameters syntax in the vm (issue 4290).

runtime/vm/raw_object.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/token.h"
@@ skipping 595 matching lines @@
   RawClass* signature_class_;  // Only for closure or signature function.
   RawCode* closure_allocation_stub_;  // Stub code for allocation of closures.
   RawFunction* implicit_closure_function_;  // Implicit closure function.
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->implicit_closure_function_);
   }
 
   intptr_t token_pos_;
   intptr_t end_token_pos_;
   intptr_t num_fixed_parameters_;
-  intptr_t num_optional_parameters_;
+  intptr_t num_optional_positional_parameters_;
+  intptr_t num_optional_named_parameters_;
   intptr_t usage_counter_;  // Incremented while function is running.
   intptr_t deoptimization_counter_;
   intptr_t kind_tag_;
 };
 
 
 class RawField : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Field);
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->name_); }
@@ skipping 963 matching lines @@
          kExternalUint64ArrayCid == kByteArrayCid + 18 &&
          kExternalFloat32ArrayCid == kByteArrayCid + 19 &&
          kExternalFloat64ArrayCid == kByteArrayCid + 20 &&
          kStacktraceCid == kByteArrayCid + 21);
   return (index >= kByteArrayCid && index <= kExternalFloat64ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_