Bug 1663725 - Add reported test as a crashtest (the crash bug itself was fixed by bug 1663601) r=m_kato

Differential Revision: https://phabricator.services.mozilla.com/D95127

editor/libeditor/crashtests/1663725.html

@@ -0,0 +1,13 @@
+<script>
+window.onload = () => {
+  document.execCommand("insertHorizontalRule", false)
+  window.getSelection().collapse(b)
+  document.execCommand("forwardDelete", false)
+}
+function go() {
+  document.getSelection().setPosition(a)
+}
+</script>
+<pre id="a">
+<time contenteditable>a|</t>
+<input id="b" onfocus="go()" autofocus onblur="go()">

editor/libeditor/crashtests/crashtests.list

@@ -130,3 +130,4 @@ load 1645983-1.html
 load 1645983-2.html
 load 1648564.html
 load 1659717.html
+load 1663725.html # throws