Allow 'storage' in backend identifiers.

Fixes: #1164

bin/varnishtest/tests/r01164.vtc

+varnishtest "Regression test for #1163: allow backends to be named storage*"
+
+varnish v1 -vcl {
+	backend storage_foo {
+		.host = "127.0.0.1";
+	}
+
+	sub vcl_recv {
+		set req.backend = storage_foo;
+	}	    
+}
+
+varnish v1 -vcl {
+	backend storagefoo {
+		.host = "127.0.0.1";
+	}
+
+	sub vcl_recv {
+		set req.backend = storagefoo;
+	}	
+}
+
+

lib/libvcl/vcc_compile.c

@@ -599,7 +599,7 @@ vcc_CompileSource(const struct vcc *tl0, struct vsb *sb, struct source *sp)
 		sym->r_methods = v->r_methods;
 	}
 
-	sym = VCC_AddSymbolStr(tl, "storage", SYM_WILDCARD);
+	sym = VCC_AddSymbolStr(tl, "storage.", SYM_WILDCARD);
 	sym->wildcard = vcc_Stv_Wildcard;
 
 	vcl_output_lang_h(tl->fh);