fix build break (#14049)

Author: vladima

tests/baselines/reference/packageJsonMain.js

@@ -28,6 +28,7 @@ foo + bar + baz;
 
 //// [a.js]
 "use strict";
+exports.__esModule = true;
 var foo = require("foo");
 var bar = require("bar");
 var baz = require("baz");

tests/baselines/reference/packageJsonMain_isNonRecursive.js

@@ -16,3 +16,4 @@ import foo = require("foo");
 
 //// [a.js]
 "use strict";
+exports.__esModule = true;

tests/baselines/reference/typingsLookup4.js

@@ -38,6 +38,7 @@ exports.__esModule = true;
 exports.l = 2;
 //// [index.js]
 "use strict";
+exports.__esModule = true;
 exports.m = 3;
 //// [a.js]
 "use strict";