update types of [[GeneratorState]] and [[AsyncGeneratorState]]

Author: michaelficarra

spec.html

@@ -48048,7 +48048,7 @@ <h1>Properties of Generator Instances</h1>
               [[GeneratorState]]
             </td>
             <td>
-              *undefined*, ~suspended-start~, ~suspended-yield~, ~executing~, or ~completed~
+              ~suspended-start~, ~suspended-yield~, ~executing~, or ~completed~
             </td>
             <td>
               The current execution state of the generator.
@@ -48392,7 +48392,7 @@ <h1>Properties of AsyncGenerator Instances</h1>
           </thead>
           <tr>
             <td>[[AsyncGeneratorState]]</td>
-            <td>*undefined*, ~suspended-start~, ~suspended-yield~, ~executing~, ~awaiting-return~, or ~completed~</td>
+            <td>~suspended-start~, ~suspended-yield~, ~executing~, ~awaiting-return~, or ~completed~</td>
             <td>The current execution state of the async generator.</td>
           </tr>
           <tr>