Fix test failures by correctly including AwaitExpression in left-hand side expression check

Co-authored-by: RyanCavanaugh <[email protected]>

Author: Copilot

tests/baselines/reference/awaitUsingDeclarations.4.errors.txt

@@ -1,17 +1,17 @@
+awaitUsingDeclarations.4.ts(2,5): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 awaitUsingDeclarations.4.ts(2,11): error TS2304: Cannot find name 'using'.
 awaitUsingDeclarations.4.ts(2,18): error TS2304: Cannot find name 'a'.
-awaitUsingDeclarations.4.ts(2,21): error TS1005: ';' expected.
 
 
 ==== awaitUsingDeclarations.4.ts (3 errors) ====
     {
         await using [a] = null;
+        ~~~~~~~~~~~~~~~
+!!! error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
               ~~~~~
 !!! error TS2304: Cannot find name 'using'.
                      ~
 !!! error TS2304: Cannot find name 'a'.
-                        ~
-!!! error TS1005: ';' expected.
     }
 
     export {};

tests/baselines/reference/awaitUsingDeclarations.4.js

@@ -9,7 +9,6 @@ export {};
 
 //// [awaitUsingDeclarations.4.js]
 {
-    await using[a];
-    null;
+    await using[a] = null;
 }
 export {};