* 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.
