Add "has storage access" boolean to environment

This is a concept that originated in the Storage Access API, where it
has been stuck because of spec issues between Fetch and 6265bis. To
un-logjam this, I've started whatwg/fetch#1807.
That depends on this bit existing.

This patch adds the bit, which remains false, and does nothing.

Author: bvandersloot-mozilla

source

@@ -108066,6 +108066,11 @@ new PaymentRequest(…); // Allowed to use
    for="environment">execution ready flag</dfn></dt>
    <dd><p>A flag that indicates whether the environment setup is done. It is initially
    unset.</p></dd>
+
+   <dt>A <dfn data-x="concept-environment-has-storage-access" export
+    for="environment">has storage access</dfn></dt>
+    <dd><p>A boolean that indicates whether the environment has access to unpartitioned
+    cookies. It is initially false.</p></dd>
   </dl>
 
   <p>Specifications may define <dfn export>environment discarding steps</dfn> for environments. The