Whenever possible, use the vertical bar as sed delimiter.

Whenever possible, use the vertical bar as sed delimiter.

* lib/autoconf/functions.m4 (GETLOADAVG_LIBS) [AC_FUNC_GETLOADAVG]:
Use "|", not "!".
* lib/autoconf/status.m4 (_AC_SRCDIRS) [ac_top_builddir_sub]:
[ac_dir_suffix]: Use "|", not "," as sed delimiter.
* tests/mktests.sh (as_me): Likewise.
* lib/freeze.mk (check-forbidden-patterns): Likewise.
* lib/autoconf/fortran.m4 (_AC_PROG_FC_V_OUTPUT): Likewise.
* configure: Regenerate.
* doc/autoconf.texi (Shell Substitutions): Use "|", not "," in examples.
* lib/autotest/general.m4 (AT_INIT): Use "|", not "&" as sed delimiter
in the : -> $PATH_SEPARATOR transformation of $AUTOTEST_PATH.  This is fine,
as long as $PATH_SEPARATOR doesn't contain "|".