Constify three strings in compiled VCL data structure vrt_backend

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@3229 d4fa192b-c00b-0410-8231-f00ffab90ce4

include/vrt.h

@@ -60,10 +60,10 @@ struct vrt_backend_probe {
  * A backend is a host+port somewhere on the network
  */
 struct vrt_backend {
-	char				*vcl_name;
-	char				*ident;
+	const char			*vcl_name;
+	const char			*ident;
 
-	char				*hosthdr;
+	const char			*hosthdr;
 
 	const unsigned char		*ipv4_sockaddr;
 	const unsigned char		*ipv6_sockaddr;

lib/libvcl/vcc_fixed_token.c

@@ -340,10 +340,10 @@ vcl_output_lang_h(struct vsb *sb)
 	vsb_cat(sb, " * A backend is a host+port somewhere on the network\n");
 	vsb_cat(sb, " */\n");
 	vsb_cat(sb, "struct vrt_backend {\n");
-	vsb_cat(sb, "	char				*vcl_name;\n");
-	vsb_cat(sb, "	char				*ident;\n");
+	vsb_cat(sb, "	const char			*vcl_name;\n");
+	vsb_cat(sb, "	const char			*ident;\n");
 	vsb_cat(sb, "\n");
-	vsb_cat(sb, "	char				*hosthdr;\n");
+	vsb_cat(sb, "	const char			*hosthdr;\n");
 	vsb_cat(sb, "\n");
 	vsb_cat(sb, "	const unsigned char		*ipv4_sockaddr;\n");
 	vsb_cat(sb, "	const unsigned char		*ipv6_sockaddr;\n");