* libc/stdlib/abort.c: changed description: uses "raise" instead of
"getpid" and "kill"; added: uses "write" and "_exit".
Also included unistd.h for "_exit" prototype.
* libc/stdlib/system.c: included unistd.h for "execve" prototype,
reent.h for "_fork_r" and "_wait_r" prototypes.
(do_system): changed extern char *environ[] to POSIX-friendly
extern char **environ.
* libc/stdlib/wctomb_r.c: included string.h for "strlen" and "strcmp"
prototypes.
* libc/stdlib/remove.c: included reent.h for "_unlink_r" prototype.
* libc/reent/execr.c: included sys/wait.h for "wait" prototype.
* libc/reent/fstatr.c: included sys/stat.h for "fstat" prototype.
* libc/reent/openr.c: included fcntl.h for "open" prototype.
* libc/reent/signalr.c: included signal.h for "kill" prototype,
unistd.h for "getpid" prototype.
* libc/reent/statr.c: included sys/stat.h for "stat" prototype.
* libc/reent/timer.c: included sys/time.h for "gettimeofday" prototype.
* libc/unix/getut.c (utmpname): removed local, incorrect "strdup"
prototype. Also included stdlib.h for "abort", string.h for
"strdup" and "strncmp" prototypes.
* libc/unix/getlogin.c: included string.h for "strncmp", "memset", and
"strncpy", unistd.h for "read" and "close" prototypes.
* libc/posix/execvp.c: included string.h for "strchr", "strlen", and
"strcat" prototypes.
* libc/stdlib/envlock.c: changed documented "__env_lock" and
"__env_unlock" prototype from "void *" or "char *" to
"struct _reent *" to match real function. Also added include
of envlock.h.
* libc/stdlib/mlock.c: changed documented "__malloc_lock" and
"__malloc_unlock" prototype from "void *" or "char *" to
"struct _reent *" to match real function.
* libc/stdlib/envlock.h: added "__env_lock" and "__env_unlock"
prototypes (for getenv_r.c and setenv_r.c).
* libc/include/sys/reent.h (_rand_next): Added __extension__
qualifier as long long type is not strict ANSI.
* libc/stdlib/rand.c (rand): Added __extension__ qualifier
to long long constant.
* libc/include/sys/reent.h (_rand_next): Changed to
unsigned long long and moved to end of _reent struct in _new union.
(_REENT_INIT): Changed to move _rand_next initialization.
* libc/stdlib/rand.c (rand): Changed to use unsigned long long
linear congruential algorithm that is used by DJGPP.