ci: exercise the whole test suite with uncommon code in pack-objects

Some recent optimizations have been added to pack-objects to reduce
memory usage and some code paths are split into two: one for common
use cases and one for rare ones. Make sure the rare cases are tested
with Travis since it requires manual test configuration that is
unlikely to be done by developers.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ci/run-build-and-tests.sh

@@ -11,7 +11,10 @@ make --jobs=2
 make --quiet test
 if test "$jobname" = "linux-gcc"
 then
-	GIT_TEST_SPLIT_INDEX=yes make --quiet test
+	export GIT_TEST_SPLIT_INDEX=yes
+	export GIT_TEST_FULL_IN_PACK_ARRAY=true
+	export GIT_TEST_OE_SIZE=10
+	make --quiet test
 fi
 
 check_unignored_build_artifacts