Initialize the home object when we create the initializer function
keeping this in line with other functions that initialize home object.

Bug: v8:5367
Change-Id: I1c5e32ae0cb496740341e6c99c9359f6c5e00875
Reviewed-on: https://chromium-review.googlesource.com/754163Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49153}