r600/sb: fix a bug emitting ar load from a constant.

Some tess shaders were doing MOVA_INT _, c0.x on cayman, and then
hitting an assert in sb_bc_finalize.cpp:translate_kcache.

This makes sure the toplevel kcache tracker gets updated,
and the clause gets fixed up.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Cc: <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/gallium/drivers/r600/sb/sb_sched.cpp

@@ -1130,6 +1130,9 @@ void post_scheduler::emit_clause() {
 	if (alu.current_ar) {
 		emit_load_ar();
 		process_group();
+		if (!alu.check_clause_limits()) {
+			// Can't happen since clause only contains MOVA/CF_SET_IDX0/1
+		}
 		alu.emit_group();
 	}