* libunwind-frame.h (struct regcache): Add forward declaration.

	* libunwind-frame.h (struct regcache): Add forward declaration.
	(libunwind_get_reg_special): Add REGCACHE argument.
	* libunwind-frame.c (libunwind_get_reg_special): Add REGCACHE
	argument.  Pass it to unw_init_remote_p.

	* ia64-tdep.c (ia64_pseudo_register_read): Pass regcache to
	libunwind_get_reg_special.
	(ia64_access_reg): Remove "write" case.
	(ia64_access_fpreg): Likewise.  Read from next_frame passed
	as callback argument instead of from current_regcache.
	(ia64_access_rse_reg): Remove "write" case.  Read from regcache
	passed as callback argument instead of from current_regcache.
	(ia64_access_rse_fpreg): New function.
	(ia64_unw_rse_acce): Use it instead of ia64_access_fpreg.