Allow document.open()/write() to be called on non-active documents

There is no longer anything fundamental that prevents document.open()
from being useful on non-active documents. This also aligns with Chrome,
Edge, and Safari. In fact, some developers already utilize this property
as a streaming HTML parser to desirable effect (see whatwg#2827).

Additionally, use a more appropriate guard for erasing event listeners
and handlers on the Window object, as revealed by the tests.

Fixes whatwg#2827.

Tests: web-platform-tests/wpt#12636
Tests: web-platform-tests/wpt#12770

source

@@ -90970,12 +90970,6 @@ document.body.appendChild(frame)</code></pre>
    than 0, then throw an <span>"<code>InvalidStateError</code>"</span>
    <code>DOMException</code>.</p></li>
 
-   <li><p>If <var>document</var> is not an <span>active document</span>, then return
-   <var>document</var>.</p></li>
-
-   <li><p>Let <var>window</var> be <var>document</var>'s <span>relevant global
-   object</span>.</p></li>
-
    <li><p>Let <var>entryDocument</var> be the <span>responsible document</span> specified by the
    <span>entry settings object</span>.</p></li>
 
@@ -91002,13 +90996,17 @@ document.body.appendChild(frame)</code></pre>
     handler while the <code>Document</code> is being unloaded.</p>
    </li>
 
-   <li><p><span data-x="abort a document">Abort</span> <var>document</var>.</p></li>
+   <li><p>If <var>document</var> is an <span>active document</span>, then <span data-x="abort a
+   document">abort</span> <var>document</var>.</p></li>
 
    <li><p>For each <span>shadow-including inclusive descendant</span> <var>node</var> of
    <var>document</var>, <span>erase all event listeners and handlers</span> given
    <var>node</var>.</p></li>
 
-   <li><p><span>Erase all event listeners and handlers</span> given <var>window</var>.</p></li>
+   <li><p>If <var>document</var> is the <span data-x="concept-document-window">associated
+   <code>Document</code></span> of <var>document</var>'s <span>relevant global object</span>, then
+   <span>erase all event listeners and handlers</span> given <var>document</var>'s <span>relevant
+   global object</span>.</p></li>
 
    <li><p><span data-x="concept-node-replace-all">Replace all</span> with null within
    <var>document</var>, without firing any mutation events.</p></li>
@@ -91199,8 +91197,6 @@ document.body.appendChild(frame)</code></pre>
    than 0, then throw an <span>"<code>InvalidStateError</code>"</span>
    <code>DOMException</code>.</p></li>
 
-   <li><p>If <var>document</var> is not an <span>active document</span>, then return.</p></li>
-
    <li>
     <p>If the <span>insertion point</span> is undefined, then: