Build upon URL rather than PSL

Instead of "parsing" the Public Suffix List directly, use new terminology from the URL Standard.

Fixes #3711.

source

@@ -2663,6 +2663,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x="concept-domain" data-x-href="https://url.spec.whatwg.org/#concept-domain">domain</dfn></li>
      <li><dfn data-x-href="https://url.spec.whatwg.org/#concept-ipv4">IPv4 address</dfn></li>
      <li><dfn data-x-href="https://url.spec.whatwg.org/#concept-ipv6">IPv6 address</dfn></li>
+     <li><dfn data-x-href="https://url.spec.whatwg.org/#host-same-site">same site</dfn></li>
      <li><dfn data-x-href="https://url.spec.whatwg.org/#concept-url">URL</dfn></li>
      <li><dfn data-dfn-for="url" data-x="concept-url-origin" data-x-href="https://url.spec.whatwg.org/#concept-url-origin">Origin</dfn> of URLs</li>
      <li><dfn data-x-href="https://url.spec.whatwg.org/#syntax-url-absolute">Absolute URL</dfn></li>
@@ -79671,33 +79672,8 @@ interface <dfn>BarProp</dfn> {
 
    <li><p>If <var>host</var> is failure, then return false.</p></li>
 
-   <li>
-    <p>If <var>host</var> is <em>not</em> <span data-x="host equals">equal</span> to
-    <var>originalHost</var>, then run these substeps:</p>
-
-    <ol>
-     <li>
-      <p>If <var>host</var> or <var>originalHost</var> is not a <span
-      data-x="concept-domain">domain</span>, then return false.</p>
-
-      <p class="note">This is meant to exclude <span data-x="concept-host">hosts</span> that are an
-      <span>IPv4 address</span> or an <span>IPv6 address</span>.</p>
-     </li>
-
-     <li><p>If <var>host</var>, prefixed by a U+002E FULL STOP (.), does not exactly match the end
-     of <var>originalHost</var>, then return false.</p></li>
-
-     <li>
-      <p>If <var>host</var> matches a suffix in the Public Suffix List, or, if <var>host</var>,
-      prefixed by a U+002E FULL STOP (.), matches the end of a suffix in the Public Suffix List,
-      then return false. <ref spec=PSL></p>
-
-      <p>Suffixes must be compared after applying the <span>host parser</span> algorithm.</p>
-     </li>
-    </ol>
-   </li>
-
-   <li><p>Return true.</p></li>
+   <li><p>Return true if <var>host</var> is <span>same site</span> with <var>originalHost</var>, and
+   false otherwise.</p></li>
   </ol>
 
   <p>The <dfn><code data-x="dom-document-domain">domain</code></dfn> attribute's getter must run