ld: text segment should not be writable

R=adg
CC=golang-dev
https://golang.org/cl/3708041
diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index ca580b5..210f10a 100644
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -857,7 +857,7 @@
 	uvlong va;
 
 	va = INITTEXT;
-	segtext.rwx = 07;
+	segtext.rwx = 05;
 	segtext.vaddr = va;
 	segtext.fileoff = HEADR;
 	for(s=segtext.sect; s != nil; s=s->next) {