From cc477ee891270e2a3af820e2cc6889ddc65c63af Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <DanielRosenwasser@users.noreply.github.com>
Date: Mon, 10 Dec 2018 17:16:23 -0800
Subject: [PATCH 1/2] Only use 'es2015.iterable' to avoid accidental es2015
 feature usage.

---
 src/tsconfig-base.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tsconfig-base.json b/src/tsconfig-base.json
index e9925f3a98b22..4d83436a5385a 100644
--- a/src/tsconfig-base.json
+++ b/src/tsconfig-base.json
@@ -1,7 +1,7 @@
 {
     "compilerOptions": {
         "pretty": true,
-        "lib": ["es2015"],
+        "lib": ["es2015.iterable", "es5"],
         "target": "es5",
         "rootDir": ".",
 

From 28c3663e6218c61929d74dda1cdd8bcf042a3f6a Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <Daniel.Rosenwasser@microsoft.com>
Date: Mon, 10 Dec 2018 17:45:51 -0800
Subject: [PATCH 2/2] Don't use 'fill' in 'fill'.

---
 src/compiler/core.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index f585ce2ec9678..322355117ec2c 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -2165,6 +2165,10 @@ namespace ts {
     }
 
     export function fill<T>(length: number, cb: (index: number) => T): T[] {
-        return new Array(length).fill(0).map((_, i) => cb(i));
+        const result = Array<T>(length);
+        for (let i = 0; i < length; i++) {
+            result[i] = cb(i);
+        }
+        return result;
     }
 }