VM.assert(n <= NUMBER_DOUBLE_PARAM);
VM._assert(n <= NUMBER_DOUBLE_PARAM);
  Enumeration enumerateFPRParameters(int n) {    if (VM.VerifyAssertions)      VM.assert(n <= NUMBER_DOUBLE_PARAM);    return new PhysicalRegisterEnumeration(FIRST_DOUBLE_PARAM,                                           FIRST_DOUBLE_PARAM + n - 1);  }