Fix import() inside setTimeout()/setInterval() strings

Closes #3116. Before this change, the "new script"-ness of setTimeout()
and setInterval()'s string compilation was making any import() calls
inside the compiled source behave unexpectedly. After this, they behave
like eval().

source

@@ -91051,6 +91051,8 @@ document.body.appendChild(frame)</pre>
    <li><p>Let <var>callerRealm</var> be the <span>current Realm Record</span>, and
    <var>calleeRealm</var> be <var>method context</var>'s <span>JavaScript realm</span>.</p></li>
 
+   <li><p>Let <var>activeScript</var> be the <span>active script</span>.</p></li>
+
    <li>
 
     <p>Let <var>task</var> be a <span data-x="concept-task">task</span> that runs the
@@ -91085,20 +91087,39 @@ document.body.appendChild(frame)</pre>
         <ol>
          <li><p>Perform <span
          data-x="the-hostensurecancompilestrings-implementation">HostEnsureCanCompileStrings</span>(<var>callerRealm</var>,
-         <var>calleeRealm</var>). If this throws an exception, catch it, and <span>report the
-         exception</span>.</p></li>
+         <var>calleeRealm</var>). If this throws an exception, catch it, <span>report the
+         exception</span>, and abort these steps.</p></li>
 
          <li><p>Let <var>script source</var> be the first method argument.</p></li>
 
          <li><p>Let <var>settings object</var> be <var>method context</var>'s <span>environment
          settings object</span>.</p></li>
 
-         <li><p>Let <var>base URL</var> be <var>settings object</var>'s <span>API base
-         URL</span>.</p></li>
+         <li><p>Let <var>base URL</var> be <var>active script</var>'s <span
+         data-x="concept-script-base-url">base URL</span>.</p></li>
+
+         <li>
+          <p>Let <var>fetch options</var> be a <span>script fetch options</span> whose <span
+          data-x="concept-script-fetch-options-nonce">cryptographic nonce</span> is <var>active
+          script</var>'s <span data-x="concept-script-script-fetch-options">fetch options</span>'s
+          <span data-x="concept-script-fetch-options-nonce">cryptographic nonce</span>, <span
+          data-x="concept-script-fetch-options-integrity">integrity metadata</span> is the empty
+          string, <span data-x="concept-script-fetch-options-parser">parser metadata</span> is
+          "<code data-x="">not-parser-inserted</code>", and <span
+          data-x="concept-script-fetch-options-credentials">credentials mode</span> is <var>active
+          script</var>'s <span data-x="concept-script-script-fetch-options">fetch options</span>'s
+          <span data-x="concept-script-fetch-options-credentials">credentials mode</span>.</p>
+
+          <p class="note">The effect of these options ensures that the string compilation done by
+          <code data-x="dom-setTimeout">setTimeout()</code> and <code
+          data-x="dom-setInterval">setInterval()</code> behaves equivalently to that done by
+          <code>eval()</code>. That is, <span>module script</span> fetches via <code>import()</code>
+          will behave the same in both contexts.</p>
+         </li>
 
          <li><p>Let <var>script</var> be the result of <span>creating a classic script</span> given
-         <var>script source</var>, <var>settings object</var>, <var>base URL</var>, and the
-         <span>default classic script fetch options</span>.</p></li>
+         <var>script source</var>, <var>settings object</var>, <var>base URL</var>, and <var>fetch
+         options</var>.</p></li>
 
          <li><p><span data-x="run a classic script">Run the classic script</span>
          <var>script</var>.</p></li>