t7004: move limited stack prereq to test-lib

The lazy prerequisite  ULIMIT_STACK_SIZE is used only in t7004 so far.

Move it to test-lib.sh so that it can be used in other tests (which it will
be in a follow-up commit).

Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: mjg

t/t7004-tag.sh

@@ -1863,12 +1863,6 @@ test_expect_success 'version sort with very long prerelease suffix' '
 	git tag -l --sort=version:refname
 '
 
-run_with_limited_stack () {
-	(ulimit -s 128 && "$@")
-}
-
-test_lazy_prereq ULIMIT_STACK_SIZE 'run_with_limited_stack true'
-
 # we require ulimit, this excludes Windows
 test_expect_success ULIMIT_STACK_SIZE '--contains and --no-contains work in a deep repo' '
 	>expect &&

t/test-lib.sh

@@ -1167,6 +1167,12 @@ run_with_limited_cmdline () {
 
 test_lazy_prereq CMDLINE_LIMIT 'run_with_limited_cmdline true'
 
+run_with_limited_stack () {
+	(ulimit -s 128 && "$@")
+}
+
+test_lazy_prereq ULIMIT_STACK_SIZE 'run_with_limited_stack true'
+
 build_option () {
 	git version --build-options |
 	sed -ne "s/^$1: //p"