From 072089f0ecd63836a3d66f1dd63f399f9c0da85e Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 21 Sep 2015 15:43:49 -0700
Subject: [PATCH] Downlevel emit for **=

---
 src/compiler/emitter.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 6ddf868efe1..541488bd82b 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -2523,7 +2523,12 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         write(`", `);
                     }
 
-                    if (languageVersion < ScriptTarget.ES7 && node.operatorToken.kind === SyntaxKind.AsteriskAsteriskToken) {
+                    if (languageVersion < ScriptTarget.ES7 &&
+                        (node.operatorToken.kind === SyntaxKind.AsteriskAsteriskToken || node.operatorToken.kind === SyntaxKind.AsteriskAsteriskEqualsToken)) {
+                        if (node.operatorToken.kind === SyntaxKind.AsteriskAsteriskEqualsToken) {
+                            emit(node.left);
+                            write(" = ");
+                        }
                         write("Math.pow(");
                         emit(node.left);
                         write(", ");