alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c

Turn the slow side of work_pending into C function, including all
the looping.  What we get out of that:
	* we do _not_ call get_signal_to_deliver() with IRQs disabled
anymore
	* no need to save/restore volatiles on each pass if there
turns to be more than one (unlikely, but still)
	* all double-restart prevention is in C now.
	* glue gets simpler.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index 802108b..0c30cce 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -390,15 +390,9 @@
 	bsr	$1, do_switch_stack
 	mov	$sp, $17
 	mov	$5, $18
-	mov	$19, $9		/* save old syscall number */
-	mov	$20, $10	/* save old a3 */
-	and	$5, _TIF_SIGPENDING, $2
-	cmovne	$2, 0, $9	/* we don't want double syscall restarts */
-	jsr	$26, do_notify_resume
-	mov	$9, $19
-	mov	$10, $20
+	jsr	$26, do_work_pending
 	bsr	$1, undo_switch_stack
-	br	ret_to_user
+	br	restore_all
 .end work_pending
 
 /*