When building libbacktrace, we typically use elf.c, and don't build pecoff.c,
xcoff.c or unknown.c.
Add testcases that use unused format to ensure that we also build and
test those on a typical development setup.
Bootstrapped and reg-tested on x86_64.
2018-11-30 Tom de Vries <tdevries@suse.de>
* Makefile.am (check_PROGRAMS): Add test_elf, test_xcoff_32,
test_xcoff_64, test_pecoff and test_unknown.
* Makefile.in: Regenerate.
* test_format.c: New file.
From-SVN: r266668
