Allow mutating <input disabled type=checkbox/radio>

Fixes whatwg#5000.

Tests: web-platform-tests/wpt#24975

source

@@ -44700,8 +44700,9 @@ interface <dfn>HTMLInputElement</dfn> : <span>HTMLElement</span> {
   agent should not allow the user to modify the element's <span
   data-x="concept-fe-value">value</span> or <span data-x="concept-fe-checked">checkedness</span>.</p>
 
-  <p>When an <code>input</code> element is <span
-  data-x="concept-fe-disabled">disabled</span>, it is not <i
+  <p>When an <code>input</code> element is <span data-x="concept-fe-disabled">disabled</span> and
+  is not in the <span data-x="attr-input-type-checkbox">Checkbox</span> nor <span
+  data-x="attr-input-type-radio">Radio</span> states, it is not <i
   data-x="concept-fe-mutable">mutable</i>.</p>
 
   <p class="note">The <code data-x="attr-input-readonly">readonly</code> attribute can also in some
@@ -44719,7 +44720,9 @@ interface <dfn>HTMLInputElement</dfn> : <span>HTMLElement</span> {
   <p>The <span>activation behavior</span> for <code>input</code> elements are these steps:</p>
 
   <ol>
-   <li><p>If this element is not <i data-x="concept-fe-mutable">mutable</i>, then return.</p></li>
+   <li><p>If this element is not <i data-x="concept-fe-mutable">mutable</i> and is not in <span
+   data-x="attr-input-type-checkbox">Checkbox</span> nor <span data-x="attr-input-type-radio">
+   Radio</span>, then return.</p></li>
 
    <li><p>Run this element's <dfn>input activation behavior</dfn>, if any, and do nothing
    otherwise.</p></li>