Fix some of the compiling warnings

This patch removes the "unused-parameter" warnings generated by the origin code
and the multiple definition warnings for _LIBUNWIND_BUILD_ZERO_COST_APIS macro.

Signed-off-by: Costin Lupu <costin.lupu@cs.pub.ro>
Reviewed-by: Felipe Huici <felipe.huici@neclab.eu>

Initial port of Libunwind to Unikraft

This is our initial port of libunwind to Unikraft as an external
library. Libc, or an equivalent, is required for it to work.

The dependency list in the  Makefile should be:
...:$(UK_LIBS)/libunwind:$(UK_LIBS)/compiler-rt:
$(UK_LIBS)/libcxxabi:$(UK_LIBS)/libcxx:$(UK_LIBS)/newlib:...

Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@stud.acs.upb.ro>
Reviewed-by: Felipe Huici <felipe.huici@neclab.eu>

Add .gitignore

Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@stud.acs.upb.ro>
Reviewed-by: Felipe Huici <felipe.huici@neclab.eu>

Initial commit (empty)