(ia64_regnum_t): Define well-known frame registers here and add
TDEP-aliases for use by libunwind.h.
(unw_ia64_table_t): Use unw_tdep_word_t instead of unw_word_t so this
file can be included by libunwind.h.
Change type of "array" member to void *. On OSes that support
ILP32, it may point to a 32-bit unwind table.
(Logical change 1.5)