Ports over microsoft#129

Author: orta

package.json

@@ -2,7 +2,7 @@
     "name": "tslib",
     "author": "Microsoft Corp.",
     "homepage": "https://www.typescriptlang.org/",
-    "version": "1.14.0",
+    "version": "1.14.1",
     "license": "0BSD",
     "description": "Runtime library for TypeScript helper functions",
     "keywords": [
@@ -28,6 +28,7 @@
     "sideEffects": false,
     "exports": {
         ".": {
+            "module": "./tslib.es6.js",
             "import": "./modules/index.js",
             "default": "./tslib.js"
         },