new switch implementation
in preparation of type switch.
no functional change (yet).

R=r
OCL=25784
CL=25788
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 76e440d..dfd975f 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -812,8 +812,7 @@
 void	walkconv(Node*);
 void	walkas(Node*);
 void	walkbool(Node*);
-Type*	walkswitch(Node*, Type*(*)(Node*, Type*));
-int	casebody(Node*);
+void	walkswitch(Node*);
 void	walkselect(Node*);
 int	whatis(Node*);
 void	walkdot(Node*);