compiler changes:
	export.c:
		- only expose explicitly exported types to importer
		- fix behind your back
	go.h:
		- add deep() prototype (fixes 64-bit linux crash on time.go)
	go.y:
		- add a new syntax error case
	walk.c:
		- allow a,b = f() where f is func ptr (fixes bug088)

R=ken
OCL=15617
CL=15630
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 303c8cc..d80f6e7 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -729,3 +729,4 @@
 void	argspace(int32);
 Node*	nodarg(Type*, int);
 void	nodconst(Node*, Type*, vlong);
+Type*	deep(Type*);