illumos gate

Currently /usr/include/netinet/in.h defines

struct in6_addr {
        union {
                /*
                 * Note: Static initalizers of "union" type assume
                 * the constant on the RHS is the type of the first member
                 * of union.
                 * To make static initializers (and efficient usage) work,
                 * the order of members exposed to user and kernel view of
                 * this data structure is different.
                 * User environment sees specified uint8_t type as first
                 * member whereas kernel sees most efficient type as
                 * first member.
                 */
#ifdef _KERNEL
                uint32_t        _S6_u32[4];     /* IPv6 address */
                uint8_t         _S6_u8[16];     /* IPv6 address */
#else
                uint8_t         _S6_u8[16];     /* IPv6 address */
                uint32_t        _S6_u32[4];     /* IPv6 address */
#endif
                uint32_t        __S6_align;     /* Align on 32 bit boundary */
        } _S6_un;
};

We wold benefit from adding uint16_t _S6_u16⁸ to this union for porting applications, which needs s6_addr16.