VM_Address  ref_address;
  public VM_Address getNextReturnAddressAddress() {    VM_Address  ref_address;    if ( !jniSavedReturnAddr.isZero() ) {      ref_address = jniSavedReturnAddr;      jniSavedReturnAddr = VM_Address.zero();      if (verbose > 0) {	VM.sysWriteln("JNI getNextReturnAddressAddress returning ", ref_address);      }      return ref_address;    }    return VM_Address.zero();  }