cmd/6g: allow componentgen of slice inside struct

Change-Id: I847bf32bd0be913fad277c5e657f44df147eee14
Reviewed-on: https://go-review.googlesource.com/7729Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

src/cmd/6g/cgen.go

@@ -1668,7 +1668,7 @@ func componentgen(nr *gc.Node, nl *gc.Node) bool {
 		fldcount := int64(0)
 
 		for t := nl.Type.Type; t != nil; t = t.Down {
-			if gc.Isfat(t.Type) {
+			if gc.Isfat(t.Type) && !gc.Isslice(t) {
 				goto no
 			}
 			if t.Etype != gc.TFIELD {