inc/pwd.h (struct passwd): Change the types of pw_uid and pw_gid to unsigned.
(getpwuid): Argument is now unsigned.
uid_t is now unsigned.
ntlib.c (setuid): Argument is now unsigned.
(getuid): Return value is now unsigned.
(getpwuid): Argument is now unsigned.
(fchown): UID and GID arguments are now unsigned.
ntlib.h (fchown): UID and GID arguments are now unsigned.
(getuid): Return value is now unsigned.
(setuid): Argument is now unsigned.
(getpwuid): Remove prototype (it's declared in nt/inc/pwd.h).
w32.c (getpwuid): Change argument type to unsigned.
(struct w32_id): Change type of `rid' member to unsigned.
(w32_cached_id, w32_add_to_cache, get_name_and_id): Change type of
argument ID to unsigned. All callers changed.
(getuid, geteuid, getgid, getegid): Change return type to unsigned.