as sigcontext). Adjust for the fact that the RSE arithmetic
is now done on values of type unw_word_t rather than long pointers.
(ia64_scratch_loc): Rename from ia64_get_sigcontext() and expand
it such that it returns a scratch register location if
the current frame is not a sigcontext frame.
(ia64_access_reg): Read the address of the personality routine with
ia64_get() rather than trying to dereference the address
directly. When writing the IP or the PR, update the cached
values, too.
(Logical change 1.5)