remove unused var

yyx990803 · yyx990803 · commit 59dca1208b14 · 2016-06-22T10:39:36.000-04:00
diff --git a/src/core/observer/watcher.js b/src/core/observer/watcher.js
@@ -12,7 +12,6 @@ import {
 } from '../util/index'
 
 let uid = 0
-const targetStack = []
 
 /**
  * A watcher parses an expression, collects dependencies,
