test_bcj_exact_size, test_check, test_hardware, and test_index will
all now compile and skip properly if encoders or decoders are disabled.
Also fixed a small typo (disabed -> disabled).
Thanks to Sebastian Andrzej Siewior.
Created tests for all API functions exported in
src/liblzma/api/lzma/hardware.h. The tests are fairly trivial
but are helpful because they will inform users if their machines
cannot support these functions. They also improve the code
coverage metrics.
