This reverts commit a205117c.

Reason for revert: breaks Arm64

Original change's description:
> [Compiler] Remove code aging support.
> 
> Code aging is no longer supported by any remaining compilers now
> that full codegen has been removed. This CL removes all vestiges of
> code aging.
> 
> BUG=v8:6409
> 
> Change-Id: I945ebcc20c7c55120550c8ee36188bfa042ea65e
> Reviewed-on: https://chromium-review.googlesource.com/619153
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47501}

TBR=ulan@chromium.org,rmcilroy@chromium.org,marja@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org,rodolph.perfetta@arm.com

Change-Id: I9d8b2985e2d472697908270d93a35eb7ef9c88a8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6409
Reviewed-on: https://chromium-review.googlesource.com/625998Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47506}