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