[PATCH] Implement "make update-all-abi"

[Roland McGrath]

> +define update-all-abi
> +bash $(..)scripts/update-abilist.sh $^ \

$(BASH)

But what in this script is actually using a bash extension?  If it doesn't
take much effort to keep a script POSIX sh-compatible, we should do it.

> +  $$(find $(..)sysdeps \
> +    -regextype posix-egrep -regex '.*/$*([^a-z0-9].*)?\.abilist$$' \
> +    \! -regex '.*/generic/.*')
> +endef

Why isn't this find just rolled into the script?

> +if test $# -lt 3 ; then

Use [ ... ] rather than test.  No space before a ; like that.

> +    echo "usage: $0 OLD-FILE NEW-FILE FILES-TO-BE-PATCHED..." 1>&2

Two-space indent.

> +    if ! cmp -s -- "$to_be_patched" "$tmp_patched" ; then
> +	echo "info: updating $to_be_patched" 1>&2
> +	cp -- "$tmp_patched" "$to_be_patched"
> +    fi

Just call out to move-if-change for this.