But if we want to be super accurate, it's indeed different, in that the old
hugetlb code was checking stack top with STACK_TOP, which is
mips_stack_top() for MIPS: it's a value that might be slightly less than
TASK_SIZE..
So strictly speaking, there's indeed a trivial difference on the oddity of
defining stack top, but my guess is nothing will be affected. I can add
some explanation into the commit message in that case.