Update flag definitions

Author: meacer

fetch.bs

@@ -2124,6 +2124,16 @@ Unless stated otherwise, it is false.
 <p>A <a for=/>request</a> has an associated boolean <dfn export for=request>https-upgrade</dfn>.
 Unless stated otherwise, it is false.
 
+<p class=note>This flag is for exclusive use by https-upgrades algorithm.
+
+<p>A <a for=/>request</a> has an associated
+<dfn export for=request id=https-upgrade-fallback-url>https-upgrade-fallback-url</dfn>. It is a copy
+of the <a for=/>request</a>'s original <a for=/>URL</a> before <a for=/>request</a> is
+<a for="#https-upgrades-upgrade">optionally upgraded to HTTPS</a>. Unless stated otherwise, it is
+unset.
+
+<p class=note>This flag is for exclusive use by https-upgrades algorithm.
+
 <hr>
 
 <p>A <a for=/>request</a> has an associated
@@ -3089,6 +3099,7 @@ an <a>implementation-defined</a> value.
 </ol>
 </div>
 
+
 <h3 id=port-blocking>Port blocking</h3>
 
 <p class=note>New protocols can avoid the need for blocking ports by negotiating the protocol