than the int supports, it's set to 0x80000000 to indicate overflow.

msclock() is *always* overflowing, and clock_t is only 32-bits on
some platforms (specifically FreeBSD).  To "avoid" problems, just
keep subtracting UIN32_MAX from the value until it's less than INT_MAX
then cast.

This function is, of course, terrible and shouldn't actually be used,
but it should at least sorta kinda workish.