Correct [CEReactions] usage on HTMLOptionsCollection and HTMLTableRow…

…Element

In particular when setting HTMLOptionsCollection’s length, option
elements can be removed that might have descendant custom elements for
which disconnectedCallback should trigger.

When using HTMLTableRowElement’s insertCell(), a custom element can
never be inserted or affected.

Fixes WICG/webcomponents#596 and fixes
WICG/webcomponents#595.

source

@@ -7611,7 +7611,7 @@ http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C%21DOCTYPE%20html%3E..
 
   <pre class="idl">interface <dfn>HTMLOptionsCollection</dfn> : <span>HTMLCollection</span> {
   // inherits <span data-x="dom-HTMLCollection-item">item</span>(), <span data-x="dom-HTMLCollection-namedItem">namedItem</span>()
-  attribute unsigned long <span data-x="dom-HTMLOptionsCollection-length">length</span>; // shadows inherited <span data-x="dom-HTMLCollection-length">length</span>
+  [<span>CEReactions</span>] attribute unsigned long <span data-x="dom-HTMLOptionsCollection-length">length</span>; // shadows inherited <span data-x="dom-HTMLCollection-length">length</span>
   [<span>CEReactions</span>] <a href="#dom-htmloptionscollection-setter">setter</a> void (unsigned long index, <span>HTMLOptionElement</span>? option);
   [<span>CEReactions</span>] void <span data-x="dom-HTMLOptionsCollection-add">add</span>((<span>HTMLOptionElement</span> or <span>HTMLOptGroupElement</span>) element, optional (<span>HTMLElement</span> or long)? before = null);
   [<span>CEReactions</span>] void <span data-x="dom-HTMLOptionsCollection-remove">remove</span>(long index);
@@ -39015,7 +39015,7 @@ interface <dfn>HTMLTableRowElement</dfn> : <span>HTMLElement</span> {
   readonly attribute long <span data-x="dom-tr-rowIndex">rowIndex</span>;
   readonly attribute long <span data-x="dom-tr-sectionRowIndex">sectionRowIndex</span>;
   [SameObject] readonly attribute <span>HTMLCollection</span> <span data-x="dom-tr-cells">cells</span>;
-  [<span>CEReactions</span>] <span>HTMLElement</span> <span data-x="dom-tr-insertCell">insertCell</span>(optional long index = -1);
+  <span>HTMLElement</span> <span data-x="dom-tr-insertCell">insertCell</span>(optional long index = -1);
   [<span>CEReactions</span>] void <span data-x="dom-tr-deleteCell">deleteCell</span>(long index);
 };</pre>
    </dd>