fixup! Editorial: Describe WaiterList using Records

Co-authored-by: Shu-yu Guo <[email protected]>'

spec.html

@@ -37255,13 +37255,13 @@ <h1>GetWaiterList ( _block_, _i_ )</h1>
             </tr>
             <tr>
               <td>[[Waiters]]</td>
-              <td>A list of <emu-xref href="#agent">agents</emu-xref>.</td>
-              <td>The list of agents waiting on a memory location.</td>
+              <td>A list of agent signifiers.</td>
+              <td>The list of agent signifiers whose corresponding <emu-xref href="#agent">agents</emu-xref> are waiting on the memory location.</td>
             </tr>
             <tr>
               <td>[[MostRecentLeaveEvent]]</td>
-              <td>Synchronize event | *undefined*</td>
-              <td>The event of the most recent leaving of its critical section, or *undefined* if its critical section has never been entered. </td>
+              <td>Synchronize event | ~empty~</td>
+              <td>The event of the most recent leaving of its critical section, or ~empty~ if its critical section has never been entered. </td>
             </tr>
             </tbody>
           </table>
@@ -37283,7 +37283,7 @@ <h1>EnterCriticalSection ( _WL_ )</h1>
         <emu-alg>
           1. Assert: The calling agent is not in the critical section for any WaiterList Record.
           1. Wait until no agent is in the critical section for _WL_, then enter the critical section for _WL_ (without allowing any other agent to enter).
-          1. If _WL_.[[MostRecentLeaveEvent]] is not *undefined*, then
+          1. If _WL_.[[MostRecentLeaveEvent]] is not ~empty~, then
             1. NOTE: A _WL_ whose critical section has been entered at least once has a Synchronize event set by LeaveCriticalSection.
             1. Let _execution_ be the [[CandidateExecution]] field of the surrounding agent's Agent Record.
             1. Let _eventsRecord_ be the Agent Events Record in _execution_.[[EventsRecords]] whose [[AgentSignifier]] is AgentSignifier().