Add the "speculationrules" destination

Part of whatwg/html#11426, for requests initiated by the `Speculation-Rules` HTTP header.

Author: domenic

fetch.bs

@@ -1780,6 +1780,7 @@ the empty string,
 "<code>script</code>",
 "<code>serviceworker</code>",
 "<code>sharedworker</code>",
+"<code>speculationrules</code>",
 "<code>style</code>",
 "<code>track</code>",
 "<code>video</code>",
@@ -1821,13 +1822,16 @@ not always relevant and might require different behavior.
    <th>CSP directive
    <th>Features
   <tr>
-   <td rowspan=21>""
+   <td rowspan=22>""
    <td>"<code>report</code>"
-   <td rowspan=2>&mdash;
+   <td rowspan=3>&mdash;
    <td>CSP, NEL reports.
   <tr>
    <td>"<code>document</code>"
    <td>HTML's navigate algorithm (top-level only).
+  <tr>
+   <td>"<code>speculationrules</code>"
+   <td>The [:Speculation-Rules:] header
   <tr>
    <td>"<code>frame</code>"
    <td><code>child-src</code>
@@ -1887,7 +1891,7 @@ not always relevant and might require different behavior.
   <tr>
    <td>"<code>webidentity</code>"
    <td><code>connect-src</code>
-   <td><code>Federated Credential Management requests</code>
+   <td>Federated Credential Management requests
   <tr>
    <td>"<code>worker</code>"
    <td><code>child-src</code>, <code>script-src</code>, <code>worker-src</code>
@@ -7560,7 +7564,7 @@ dictionary RequestInit {
   any window; // can only be set to null
 };
 
-enum RequestDestination { "", "audio", "audioworklet", "document", "embed", "font", "frame", "iframe", "image", "json", "manifest", "object", "paintworklet", "report", "script", "sharedworker", "style",  "track", "video", "worker", "xslt" };
+enum RequestDestination { "", "audio", "audioworklet", "document", "embed", "font", "frame", "iframe", "image", "json", "manifest", "object", "paintworklet", "report", "script", "sharedworker", "speculationrules", "style",  "track", "video", "worker", "xslt" };
 enum RequestMode { "navigate", "same-origin", "no-cors", "cors" };
 enum RequestCredentials { "omit", "same-origin", "include" };
 enum RequestCache { "default", "no-store", "reload", "no-cache", "force-cache", "only-if-cached" };