Revert of PPC/s390: Reland: [TypeFeedbackVector] Store optimized code in the vector (patchset #1 id:1 of https://codereview.chromium.org/2861863003/ )

Reason for revert:
Original CL reverted.
Crashing on Canary
BUG=chromium:718891

Original issue's description:
> PPC/s390: Reland: [TypeFeedbackVector] Store optimized code in the vector
>
> Port 662aa425
>
> Original Commit Message:
>
>     Since the feedback vector is itself a native context structure, why
>     not store optimized code for a function in there rather than in
>     a map from native context to code? This allows us to get rid of
>     the optimized code map in the SharedFunctionInfo, saving a pointer,
>     and making lookup of any optimized code quicker.
>
>     Original patch by Michael Stanton <mvstanton@chromium.org>
>
> R=rmcilroy@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
> BUG=v8:6246
> LOG=N
>
> Review-Url: https://codereview.chromium.org/2861863003
> Cr-Commit-Position: refs/heads/master@{#45111}
> Committed: https://chromium.googlesource.com/v8/v8/+/d587812258c232f7b9a1f1a9a017ba3f9cea12ea

TBR=joransiu@ca.ibm.com,jyan@ca.ibm.com,michael_dawson@ca.ibm.com,rmcilroy@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:6246

Review-Url: https://codereview.chromium.org/2870703003
Cr-Commit-Position: refs/heads/master@{#45195}