testsuite: add option to only test a given endianess / bitness
To make it easier to test changes to the testsuite without a cross-compiler, add environment variables TEST_ENDIAN and TEST_BITS controlling which environment / bitness will be tested. All test run in all four modes.
jcm: removed bad options handling test since it's no longer in testsuite.
Signed-off-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Jon Masters <jcm@jonmasters.org>