* ia64-linux-nat.c (ia64_register_addr): Add gdbarch parameter,

	* ia64-linux-nat.c (ia64_register_addr): Add gdbarch parameter,
	replacing use of global current_gdbarch.
	(ia64_cannot_fetch_register, ia64_cannot_store_register): Likewise.
	(ia64_linux_fetch_register, ia64_linux_store_register): Update callers.

	* ia64-tdep.c (SIGCONTEXT_REGISTER_ADDRESS): Remove macro.
	(ia64_sigtramp_frame_init_saved_regs): Add next_frame parameter,
	replace uses of SIGCONTEXT_REGISTER_ADDRESS.
	(ia64_sigtramp_frame_cache): Update caller.