fix indirect error

x.go:3: invalid indirect of X (type int)

was
x.go:3: invalid indirect of nil

R=ken
OCL=33008
CL=33008

src/cmd/gc/subr.c

@@ -1215,7 +1215,9 @@ Nconv(Fmt *fp)
 	}
 
 	if(fp->flags & FmtSign) {
-		if(n->type == T || n->type->etype == TNIL)
+		if(n->type == T)
+			fmtprint(fp, "%#N", n);
+		else if(n->type->etype == TNIL)
 			fmtprint(fp, "nil");
 		else
 			fmtprint(fp, "%#N (type %T)", n, n->type);

src/cmd/gc/typecheck.c

@@ -221,7 +221,7 @@ reswitch:
 			goto ret;
 		}
 		if(!isptr[t->etype]) {
-			yyerror("invalid indirect of %+N", n);
+			yyerror("invalid indirect of %+N", n->left);
 			goto error;
 		}
 		ok |= Erv;