ffsl, ffsll: new modules * modules/ffsl: New file. * modules/ffsll: Likewise. * m4/ffsl.m4: Likewise. * m4/ffsll.m4: Likewise. * lib/ffsl.c: Likewise. * lib/ffsl.h: Likewise. * lib/ffsll.c: Likewise. * m4/string_h.m4 (gl_HEADER_STRING_H_BODY) (gl_HEADER_STRING_H_DEFAULTS): Add defaults. * modules/string (Makefile.am): Substitute witnesses. * lib/strings.in.h (ffsl, ffsll): Declare. * modules/ffsl-tests: New test file. * modules/ffsll-tests: Likewise. * tests/test-ffsl.c: Likewise. * tests/test-ffsll.c: Likewise. * MODULES.html.sh (Integer arithmetic functions): Mention it. * doc/glibc-functions/ffsl.texi (ffsl): Likewise. * doc/glibc-functions/ffsll.texi (ffsll): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>

The files in this directory are used in many GNU packages,
including coreutils, diffutils, and tar.
The autoconf tests required for these files are in ../m4.