musl libc doesn't support the GNU getopt extension to parse non-option
arguments when the optstring starts with '-'.
This extension is used by some utilities, notably iptables, that
currently return with errors even with perfectly valid invocations.
The patch adds the code needed by getopt.c and getopt_long.c to
implement that extension.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
SVN-Revision: 43309