This reverts commit 5847574e.

Reason for revert: Break mjsunit tests in Lite mode. You'll have to find a solution for tests using assertOptimized().

Original change's description:
> [Lite] Disable optimization for Lite mode.
> 
> BUG=v8:8293
> 
> Change-Id: I6b2e02420ab69fb1d2e24945d48b08d2bc24b0d0
> Reviewed-on: https://chromium-review.googlesource.com/c/1280526
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56795}

TBR=rmcilroy@chromium.org,delphick@chromium.org

Change-Id: I09f6c17cc325f50560329c46f06ad847f0bb021d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8293
Reviewed-on: https://chromium-review.googlesource.com/c/1290111Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56796}