... and stop checking that the native contexts of maps recorded in feedback vector
match function's native context - the feedback vector machinery already guarantees
that.

BUG=v8:6325

Change-Id: Iacd3f3a5f703694ff57b774b9658e186ad66641b
Reviewed-on: https://chromium-review.googlesource.com/490084Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44982}