Test how URL parser handles domains with empty labels

The test covers  https://url.spec.whatwg.org/#concept-ipv4-parser 6.1 item:
> 1. If part is the empty string, return input.

Related issue: jsdom/whatwg-url#82

Author: rmisev

url/urltestdata.json

@@ -3782,6 +3782,52 @@
     "search": "",
     "hash": ""
   },
+  "Domains with empty labels",
+  {
+    "input": "http://./",
+    "base": "about:blank",
+    "href": "http://./",
+    "origin": "http://.",
+    "protocol": "http:",
+    "username": "",
+    "password": "",
+    "host": ".",
+    "hostname": ".",
+    "port": "",
+    "pathname": "/",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "http://../",
+    "base": "about:blank",
+    "href": "http://../",
+    "origin": "http://..",
+    "protocol": "http:",
+    "username": "",
+    "password": "",
+    "host": "..",
+    "hostname": "..",
+    "port": "",
+    "pathname": "/",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "http://0..0x300/",
+    "base": "about:blank",
+    "href": "http://0..0x300/",
+    "origin": "http://0..0x300",
+    "protocol": "http:",
+    "username": "",
+    "password": "",
+    "host": "0..0x300",
+    "hostname": "0..0x300",
+    "port": "",
+    "pathname": "/",
+    "search": "",
+    "hash": ""
+  },
   "Broken IPv6",
   {
     "input": "http://[www.google.com]/",