Ensure schemelessly same-site handles non-domains well

Fixes #5281.

source

@@ -82034,11 +82034,12 @@ interface <dfn>BarProp</dfn> {
      data-x="concept-origin-host">host</span>, and let <var>hostB</var> be <var>B</var>'s <span
      data-x="concept-origin-host">host</span>.</p></li>
 
-     <li><p>If <var>hostA</var> <span data-x="host equals">equal</span> <var>hostB</var>, and
-     <var>hostA</var>'s <span>registrable domain</span> is non-null, then return true.</p></li>
+     <li><p>If <var>hostA</var> <span data-x="host equals">equals</span> <var>hostB</var> and
+     <var>hostA</var>'s <span>registrable domain</span> is null, then return true.</p></li>
 
-     <li><p>If <var>hostA</var>'s <span>registrable domain</span> equals <var>hostB</var>'s
-     <span>registrable domain</span> and is non-null, then return true.</p></li>
+     <li><p>If <var>hostA</var>'s <span>registrable domain</span> <span data-x="host
+     equals">equals</span> <var>hostB</var>'s <span>registrable domain</span> and is non-null, then
+     return true.</p></li>
     </ol>
    </li>
 
@@ -125964,6 +125965,7 @@ INSERT INTERFACES HERE
   Steve Orvell,
   Steve Runyon,
   Steven Bennett,
+  Steven Bingler,
   Steven Garrity,
   Steven Tate,
   Stewart Brodie,