Adding confstr() to rtems

[Aditya Upadhyay]

Hello All,

I was trying to port confstr support in rtems from freebsd. In file
unistd.h resided at location :
/development/rtems/4.12/sparc-rtems4.12/include/sys
has contains the name values only for cygwin guard.

I have added the following names values guarded by __POSIX_VISIBLE >= 200112
#if __POSIX_VISIBLE >= 199209
#define    _CS_PATH        1    /* default value of PATH */
#endif

#if __POSIX_VISIBLE >= 200112
#define    _CS_POSIX_V6_ILP32_OFF32_CFLAGS        2
#define    _CS_POSIX_V6_ILP32_OFF32_LDFLAGS    3
#define    _CS_POSIX_V6_ILP32_OFF32_LIBS        4
#define    _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS    5
#define    _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS    6
#define    _CS_POSIX_V6_ILP32_OFFBIG_LIBS        7
#define    _CS_POSIX_V6_LP64_OFF64_CFLAGS        8
#define    _CS_POSIX_V6_LP64_OFF64_LDFLAGS        9
#define    _CS_POSIX_V6_LP64_OFF64_LIBS        10
#define    _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS    11
#define    _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS    12
#define    _CS_POSIX_V6_LPBIG_OFFBIG_LIBS        13
#define    _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS    14
#endif

It is working. Please correct me if i am not going in right direction.

Thanks & Regards,
Aditya Upadhyay