xalloc-die-tests: avoid printing null pointer The test leaked "(null): memory exhausted" to stderr, or crashed for less capable printf. * modules/xalloc-die-tests (Files, Makefile.am): Wrap execution in shell script. * tests/test-xalloc-die.c (program_name): Declare. * tests/test-xalloc-die.sh (tmpfiles): New file. Signed-off-by: Eric Blake <ebb9@byu.net>