* libc/stdlib/getopt.c (getopt_internal): Rewrite to accept
data area so as to support reentrant calls. Change all callers
to fill in data area with global values and restore any changes
to the global values after call.
(__getopt_r, __getopt_long_r, __getopt_long_only_r): New routines
to support reentrancy that add a data area argument.
* libc/include/getopt.h: Add new _r routines and provide macros
so they can be called with using double-underscores.