VM.assert(isPageAligned(address) && isPageMultiple(size) && isPageMultiple(offset));
VM._assert(isPageAligned(address) && isPageMultiple(size) && isPageMultiple(offset));
  public static VM_Address mmap(VM_Address address, int size,                          int prot, int flags, int fd, long offset) {    if (VM.VerifyAssertions)      VM.assert(isPageAligned(address) && isPageMultiple(size) && isPageMultiple(offset));    return VM_Address.max();  // not implemented: requires new magic for 6 args, etc.    // VM_BootRecord bootRecord = VM_BootRecord.the_boot_record;    // return VM.sysCallXXX(bootRecord.sysMMapIP, address, size, prot, flags, fd, offset);  }