test re-use of compiled set regexen

src/tests/cached.vtc

@@ -10,6 +10,10 @@ varnish v1 -vcl+backend {
 
 	sub vcl_init {
 	        new barbaz = re2.regex("(bar)(baz)");
+		new foobar = re2.set();
+		foobar.add("foo");
+		foobar.add("bar");
+		foobar.compile();
 	}
 
 	sub vcl_recv {
@@ -24,6 +28,11 @@ varnish v1 -vcl+backend {
 		} else {
 			set resp.status = 999;
 		}
+		if (foobar.match("foo")) {
+			set resp.http.foo3 = "match";
+		} else {
+			set resp.status = 999;
+		}
 	}
 
 } -start
@@ -35,6 +44,7 @@ client c1 {
 	expect resp.http.foo0 == "barbaz"
 	expect resp.http.foo1 == "bar"
 	expect resp.http.foo2 == "baz"
+	expect resp.http.foo3 == "match"
 }
 
 client c1 -run