In C90, NULL is guaranteed to be declared in <stddef.h> and also in
<string.h>. Though the correct way to define NULL in FreeBSD is to
include <sys/_null.h>, other parts of libstand still require <string.h>
to build; therefore, we keep <string.h> in stand.h and add a note about
this;
- Removing no longer used 'Prototype' definition. Quote from bde@:
'Cruft related to getting incomplete struct declarations within
prototypes forward-declared before the structs. It doesn't mean
"prototype" but only part of a prototype-related hack. No longer
used.'
- Replacing iaddr_t with uintptr_t;
- Removing use of long double to determine alignment. Use a fixed 16 byte
alignment instead;
Reviewed by: bde
Obtained from: DragonFlyBSD (partially)
MFC after: 1 month
f497fbf5e4