revert usages of async

Author: saschanaz

lib/productions/type.js

@@ -171,8 +171,6 @@ export class Type extends Base {
 
   get generic() {
     if (this.subtype.length && this.tokens.base) {
-      if (this.tokens.base.value === "iterable" && this.tokens.async)
-        return "async iterable";
       return this.tokens.base.value;
     }
     return "";
@@ -263,7 +261,6 @@ for more information.`;
     const type_body = () => {
       if (this.union || this.generic) {
         return w.ts.wrap([
-          w.token(this.tokens.async, w.ts.generic),
           w.token(this.tokens.base, w.ts.generic),
           w.token(this.tokens.open),
           ...this.subtype.map((t) => t.write(w)),