with 64-bit longs again. This was fixed in rev.1.42 but the fix
rotted non-fatally in rev.1.105 and fatally in rev.1.137.
Many more non-egregrious casts are strictly required for conversions
from semi-opaque types to pointers, but we avoid most of them by using
types that are almost certain to be compatible with uintptr_t for
representing pointers (e.g., vm_offset_t). Here we don't really want
the u_longs, but we have them because a.out.h and its support code
doesn't use typedefs (it uses unsigned in V7 and unsigned long in
FreeBSD) and is too obsolete to fix now.