don't crash on:

package main
var x int
type x struct { a int }

R=ken
OCL=22903
CL=22903
diff --git a/src/cmd/gc/dcl.c b/src/cmd/gc/dcl.c
index aab47b6..50967b5 100644
--- a/src/cmd/gc/dcl.c
+++ b/src/cmd/gc/dcl.c
@@ -63,7 +63,7 @@
 	// if n has been forward declared,
 	// use the Type* created then
 	s = n->sym;
-	if(s->block == block) {
+	if(s->block == block && s->otype != T) {
 		switch(s->otype->etype) {
 		case TFORWSTRUCT:
 		case TFORWINTER: