convert to autotools
Remove the old build system.
Rename arch_uatomic*.h to uatomic_arch.h, to avoid conflits with
non-generated arch_*.h.
Signed-off-by: Pierre-Marc Fournier <pierre-marc.fournier@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>