Editorial: Add proper serialization of URL properties

The URL parser return port as an integer and host as either a hostname string, an integer (IPv4 address) or an array of integers (IPv6 address). For further processing by the URLPattern code these properties need to be properly converted to string.

The issue was discussed here: #202

spec.bs

@@ -22,6 +22,7 @@ spec: ECMASCRIPT; urlPrefix: https://tc39.es/ecma262/
 spec: URL; urlPrefix: https://url.spec.whatwg.org/
   type: dfn
     text: serialize an integer; url: #serialize-an-integer
+    text: host serializer; url: #concept-host-serializer
 </pre>
 
 <h2 id=urlpatterns>URL patterns</h2>
@@ -506,8 +507,8 @@ A <dfn>component</dfn> is a [=struct=] with the following [=struct/items=]:
     1. Set |protocol| to |url|'s [=url/scheme=].
     1. Set |username| to |url|'s [=url/username=].
     1. Set |password| to |url|'s [=url/password=].
-    1. Set |hostname| to |url|'s [=url/host=] or the empty string if the value is null.
-    1. Set |port| to |url|'s [=url/port=] or the empty string if the value is null.
+    1. Set |hostname| to |url|'s [=url/host=], [=host serializer|serialized=], or the empty string if the value is null.
+    1. Set |port| to |url|'s [=url/port=], [=serialize an integer|serialized=], or the empty string if the value is null.
     1. Set |pathname| to the result of [=URL path serializing=] |url|.
     1. Set |search| to |url|'s [=url/query=] or the empty string if the value is null.
     1. Set |hash| to |url|'s [=url/fragment=] or the empty string if the value is null.
@@ -1726,7 +1727,7 @@ To <dfn>convert a modifier to a string</dfn> given a [=part/modifier=] |modifier
   1. Let |dummyURL| be a new [=URL record=].
   1. Let |parseResult| be the result of running the [=basic URL parser=] given |value| with |dummyURL| as <i>[=basic URL parser/url=]</i> and [=hostname state=] as <i>[=basic URL parser/state override=]</i>.
   1. If |parseResult| is failure, then throw a {{TypeError}}.
-  1. Return |dummyURL|'s [=url/host=].
+  1. Return |dummyURL|'s [=url/host=], [=host serializer|serialized=], or empty string if it is null.
 </div>
 
 <div algorithm>
@@ -1749,7 +1750,7 @@ To <dfn>convert a modifier to a string</dfn> given a [=part/modifier=] |modifier
 <div algorithm>
   To <dfn>canonicalize a port</dfn> given a string |portValue| and optionally a string |protocolValue|:
 
-  1. If |value| is the empty string, return |value|.
+  1. If |portValue| is the empty string, return |portValue|.
   1. Let |dummyURL| be a new [=URL record=].
   1. If |protocolValue| was given, then set |dummyURL|'s [=url/scheme=] to |protocolValue|.
      <p class="note">Note, we set the [=URL record=]'s [=url/scheme=] in order for the [=basic URL parser=] to recognize and normalize default port values.</p>