This reverts commit e39c9e02.

Reason for revert: Breaks https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20debug/builds/15561

Original change's description:
> [compiler] Drive optimizations with feedback vector
> 
> For interpreted functions, use the optimized code slot in the feedback vector
> to store an optimization marker (optimize/in optimization queue) rather than
> changing the JSFunction's code object. Then, adapt the self-healing mechanism
> to also dispatch based on this optimization marker. Similarly, replace SFI
> marking with optimization marker checks in CompileLazy.
> 
> This allows JSFunctions to share optimization information (replacing shared
> function marking) without leaking this information across native contexts. Non
> I+TF functions (asm.js or --no-turbo) use a CheckOptimizationMarker shim which
> generalises the old CompileOptimized/InOptimizationQueue builtins and also
> checks the same optimization marker as CompileLazy and
> InterpreterEntryTrampoline.
> 
> Change-Id: I6826bdde7ab9a919cdb6b69bc0ebc6174bcb91ae
> Reviewed-on: https://chromium-review.googlesource.com/509716
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45901}

TBR=rmcilroy@chromium.org,mstarzinger@chromium.org,leszeks@chromium.org
No-Presubmit: true
No-Tree-Checks: true
No-Try: true

Change-Id: Ib6c2b4d90fc5f659a6dcaf3fd30321507ca9cb94
Reviewed-on: https://chromium-review.googlesource.com/532916Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45903}