fixup! note why raw guard is exempt

packages/patterns/src/patterns/patternMatchers.js

@@ -1815,6 +1815,13 @@ export const isRawGuard = specimen => matches(specimen, RawGuardShape);
 export const assertRawGuard = specimen =>
   mustMatch(specimen, RawGuardShape, 'rawGuard');
 
+// Unlike LegacyAwaitArgGuardShape, LegacyMethodGuardShape,
+// and LegacyInterfaceGuardShape, there is no need for a
+// LegacyRawGuardShape, because raw guards were introduced at
+// https://github.com/endojs/endo/pull/1831 , which was merged well after
+// https://github.com/endojs/endo/pull/1712 > Thus, there was never a
+// `klass:` form of the raw guard.
+
 /**
  * @returns {import('./types.js').RawGuard}
  */