avoid directive splicing during unlink in production mode

src/compiler/compile.js

@@ -99,6 +99,15 @@ export function compile (el, options, partial) {
  */
 
 function linkAndCapture (linker, vm) {
+ /* istanbul ignore if */
+ if (process.env.NODE_ENV === 'production') {
+ // reset directives before every capture in production
+ // mode, so that when unlinking we don't need to splice
+ // them out (which turns out to be a perf hit).
+ // they are kept in development mode because they are
+ // useful for Vue's own tests.
+ vm._directives = []
+ }
  var originalDirCount = vm._directives.length
  linker()
  var dirs = vm._directives.slice(originalDirCount)
@@ -161,7 +170,7 @@ function teardownDirs (vm, dirs, destroying) {
  var i = dirs.length
  while (i--) {
  dirs[i]._teardown()
- if (!destroying) {
+ if (process.env.NODE_ENV !== 'production' && !destroying) {
  vm._directives.$remove(dirs[i])
  }
  }