- allocate value for new AT_HWCAP2 auxiliary vector on all platforms.
- expand 'struct sysentvec' by new 'u_long *sv_hwcap2', in exactly
same way as for AT_HWCAP.
- add glibc(misc) compatible getauxv()- introduce new public libc function. This function retrieves
value for given auxiliary vector elf_aux_info() as weak reference to existing _elf_aux_info().
MFC after: 1 month