HTML Reporter: Faster "Hide passed" toggling on large test suites

Optimize the hidepassed click handler for large test suites by
avoiding internal function call overhead for the iterator, as well
as copying cost for the array. Shaves off a few milliseconds on the
q4000 demo overall from 10ms to 5ms (Chrome), and seems to move some
unattributed costs to outside the critical path.

src/core/reporters/HtmlReporter.js

@@ -259,10 +259,10 @@ export default class HtmlReporter {
       // the original urlParams in makeUrl()
       this.hidepassed = value;
       const tests = this.elementTests;
-      const length = tests.children.length;
-      const children = tests.children;
 
       if (field.checked) {
+        const length = tests.children.length;
+        const children = tests.children;
         for (let i = 0; i < length; i++) {
           const test = children[i];
           const className = test ? test.className : '';
@@ -274,13 +274,18 @@ export default class HtmlReporter {
           }
         }
 
-        for (const hiddenTest of this.hiddenTests) {
-          tests.removeChild(hiddenTest);
+        // Optimization: Avoid for-of iterator overhead.
+        for (let i = 0; i < this.hiddenTests.length; i++) {
+          tests.removeChild(this.hiddenTests[i]);
         }
       } else {
-        while (this.hiddenTests.length) {
-          tests.appendChild(this.hiddenTests.shift());
+        // Optimization: Avoid Array.shift() which would mutate the array many times.
+        // As of Chrome 126, HTMLElement.append(...hiddenTests) is still slower than
+        // calling appendChild in a loop.
+        for (let i = 0; i < this.hiddenTests.length; i++) {
+          tests.appendChild(this.hiddenTests[i]);
         }
+        this.hiddenTests.length = 0;
       }
       window.history.replaceState(null, '', updatedUrl);
     } else {