Clarify 'get the ShadowRealm global object'.

source

@@ -96625,15 +96625,15 @@ import "https://example.com/foo/../module2.mjs";</code></pre>
   <var>thisValue</var>, perform the following steps:
 
   <ol>
+   <li><p><span>Assert</span>: <var>calleeRealm</var> is a <span>synthetic realm</span></p></li>
    <li><p>If <var>thisValue</var> is null or undefined, return
    <var>calleeRealm</var>.[[GlobalObject]].</p></li>
    <li><p>If <span data-x="js-Type">Type</span>(<var>thisValue</var>) is not Object, then throw a
    TypeError.</p></li>
    <li><p>If <var>thisValue</var> is not a <span>global object</span>, then throw a
    TypeError.</p></li>
-   <li><p>If <var>thisValue</var>'s <span data-x="concept-global-object-realm">realm</span>'s <span
-   data-x="concept-realm-settings-object">environment settings object</span> is not a
-   <span>synthetic realm settings object</span>, then throw a TypeError.</p></li>
+   <li><p><span>Assert</span>: <var>thisValue</var> is
+   <var>calleeRealm</var>.[[GlobalObject]].</p></li>
    <li><p>Return <var>thisValue</var>.</p></li>
   </ol>