* lib/af_alg.c: Include sys-limits.h.
(MAX_RW_COUNT): Remove. Use replaced by SYS_BUFSIZE_MAX.
(afalg_stream): Also reject negative sizes for sendfile; they
should not happen and the code is a bit cleaner and faster this way.
* lib/safe-read.c: Include sys-limits.h.
(BUGGY_READ_MAXIMUM): Remove. All uses replaced by SYS_BUFSIZE_MAX.
* lib/sys-limits.h: New file, with values and commentary derived
from the old safe-read.c and from GNU Emacs sysdep.c.
* modules/crypto/md5, modules/crypto/sha1, modules/crypto/sha256:
* modules/crypto/sha512, modules/safe-read, modules/safe-write:
Add lib/sys-limits.h to Files section.