Add features.h

When threads are enabled, cxx library includes a 'features.h' header in its
'include/__config' header from origin. The header introduced by this patch
includes the 'sys/features.h' header from newlib.

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

Add exported symbols

This patch adds the mangled functions to the
exportsyms.uk. Due to the high number of symbols
this is a separate patch.

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

Initial port of libcxx to Unikraft

This is our initial port of libcxx to Unikraft as an external
library. Libc is requiered for it to work. The dependency list
should contain: ...:$(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)