add await

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/api/js/src/high-level/high-level.ts

@@ -503,7 +503,8 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
     ///////////////////////////////
 
     async function simplify(e : Expr<Name>) {
-       return _toExpr(check(Z3.simplify(contextPtr, e.ast)));
+       const result = await Z3.simplify(contextPtr, e.ast)       
+       return _toExpr(check(result));
     }
 
     /////////////