We reset the profiler ticks when the feedback changes. So, we should
not update the feedback when the feedback hasn't changed. Added a
check in IC::ConfigureVectorState to see if the feedback has changed
before we update the feedback.

Bug: 
Change-Id: I83f38656b52df7f687cd0c2eceac961dcd4f35f7
Reviewed-on: https://chromium-review.googlesource.com/657698
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47988}