Automated fixup of cases where firstElementChild is already code

This was a bug in the previous script

source

@@ -82196,7 +82196,7 @@ interface <dfn interface>BarProp</dfn> {
   <h4><span id="origin-isolation"></span>Origin-keyed agent clusters</h4>
 
   <dl class="domintro">
-   <dt>window.<code subdfn data-x="dom-originAgentCluster">originAgentCluster</code></dt>
+   <dt><code data-x="">window.<span subdfn data-x="dom-originAgentCluster">originAgentCluster</span></code></dt>
 
    <dd>
     <p>Returns true if this <code>Window</code> belongs to an <span>agent cluster</span> which is
@@ -91684,7 +91684,7 @@ document.querySelector("button").addEventListener("click", bound);
   <h5 id="runtime-script-errors">Runtime script errors</h5>
 
   <dl class="domintro">
-   <dt><code data-x="">self.<code subdfn data-x="dom-reportError">reportError</code>(<var>e</var>)</code></dt>
+   <dt><code data-x="">self.<span subdfn data-x="dom-reportError">reportError</span>(<var>e</var>)</code></dt>
    <dd><p>Dispatches an <code data-x="event-error">error</code> event at the global object for the
    given value <var>e</var>, in the same fashion as an unhandled exception.</p></dd>
   </dl>
@@ -94814,14 +94814,14 @@ interface mixin <dfn interface>WindowOrWorkerGlobalScope</dfn> {
 <span>WorkerGlobalScope</span> includes <span>WindowOrWorkerGlobalScope</span>;</code></pre>
 
   <dl class="domintro">
-   <dt>self.<code subdfn data-x="dom-isSecureContext">isSecureContext</code></dt>
+   <dt><code data-x="">self.<span subdfn data-x="dom-isSecureContext">isSecureContext</span></code></dt>
    <dd><p>Returns whether or not this global object represents a <span>secure context</span>. <ref
    spec=SECURE-CONTEXTS></p></dd>
 
-   <dt>self.<code subdfn data-x="dom-origin">origin</code></dt>
+   <dt><code data-x="">self.<span subdfn data-x="dom-origin">origin</span></code></dt>
    <dd><p>Returns the global object's <span>origin</span>, serialized as string.</p></dd>
 
-   <dt>self.<code subdfn data-x="dom-crossOriginIsolated">crossOriginIsolated</code></dt>
+   <dt><code data-x="">self.<span subdfn data-x="dom-crossOriginIsolated">crossOriginIsolated</span></code></dt>
    <dd><p>Returns whether scripts running in this global are allowed to use APIs that require
    cross-origin isolation. This depends on the `<code
    data-x="http-cross-origin-opener-policy">Cross-Origin-Opener-Policy</code>` and
@@ -95476,7 +95476,7 @@ enum <dfn enum>DOMParserSupportedType</dfn> {
     milliseconds.</p>
    </dd>
 
-   <dt>self.<code subdfn data-x="dom-clearTimeout">clearTimeout</code>(<var>handle</var>)</dt>
+   <dt><code data-x="">self.<span subdfn data-x="dom-clearTimeout">clearTimeout</span>(<var>handle</var>)</code></dt>
    <!-- don't mention that the handle is optional, since if omitted, the method does nothing -->
 
    <dd><p>Cancels the timeout set with <code data-x="dom-setTimeout">setTimeout()</code> or <code
@@ -95496,7 +95496,7 @@ enum <dfn enum>DOMParserSupportedType</dfn> {
     milliseconds.</p>
    </dd>
 
-   <dt>self.<code subdfn data-x="dom-clearInterval">clearInterval</code>(<var>handle</var>)</dt>
+   <dt><code data-x="">self.<span subdfn data-x="dom-clearInterval">clearInterval</span>(<var>handle</var>)</code></dt>
    <!-- don't mention that the handle is optional, since if omitted, the method does nothing -->
 
    <dd><p>Cancels the timeout set with <code data-x="dom-setInterval">setInterval()</code> or <code