Evalling multiple long strings makes compilation cache the bottleneck: See
https://bugs.chromium.org/p/v8/issues/detail?id=6779 for more information.

BUG=v8:6779

Change-Id: I0014b1aca1258a643cbeb441a82707b163f8166d
Reviewed-on: https://chromium-review.googlesource.com/649146Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47801}