For the newlib part, warnings are all from lack of sync between
libc/machine/cris/sys/signal.h and libc/include/sys/signal.h. This
commit gets them sufficiently in sync again, functionality-wise and
declaration-wise. Still, nothing is declared that isn't supported at
the system level (i.e. in libgloss system calls and handled by the
CRIS simulator in the gdb project).
Add a _REENT_ERRNO() macro to encapsulate the access to the
_errno member of struct reent. This will help to replace the
structure member with a thread-local storage object in a follow
up patch.
Replace uses of __errno_r() with _REENT_ERRNO(). Keep __errno_r() macro for
potential users outside of Newlib.
Use the same name as glibc & gnulib to indicate "newlib itself is
being compiled". This also harmonizes the codebase a bit in that
_LIBC was already used in places instead of _COMPILING_NEWLIB.
Building for bfin-elf, mips-elf, and x86_64-pc-cygwin produces
the same object code.