Add a test-case for hash_data() in vcl_recv{}

bin/varnishtest/tests/b00076.vtc

+varnishtest "hash_data() in vcl_recv{}"
+
+server s1 {
+	rxreq
+	txresp -hdr "Same: One"
+} -start
+
+varnish v1 -vcl+backend {
+    sub vcl_recv {
+	if (req.url == "/2") {
+		hash_data(req.http.foo);
+	}
+    }
+    sub vcl_hash {
+	hash_data(req.url);
+	return (lookup);
+    }
+} -start
+
+varnish v1 -cliok "param.set vsl_mask +Hash"
+
+client c1 {
+	txreq -url /1
+	rxresp
+	expect resp.status == 200
+	expect resp.http.same == One
+	txreq -url /2 -hdr "foo: /1"
+	rxresp
+	expect resp.status == 200
+	expect resp.http.same == One
+} -run