This is a reland of 4b9b9b68, which
accidentally disabled optimization after dependency changes (instead
of retrying).

TBR=jarin@chromium.org
TBR=mstarzinger@chromium.org

Original change's description:
> Reland "[turbofan] Rewrite CompilationDependencies"
>
> This is a reland of 52a10e50, after
> eliminating an invalid assumption about maps.
>
> TBR=jarin@chromium.org
> TBR=mstarzinger@chromium.org
>
> Original change's description:
> > [turbofan] Rewrite CompilationDependencies
> >
> > Instead of installing code dependencies during graph reduction,
> > install them after code generation.
> >
> > Bug: v8:7902, v8:7790
> > Change-Id: I8a3798254abb5b9ec7c295a1592aeb6b51f24c7a
> > Reviewed-on: https://chromium-review.googlesource.com/1119913
> > Commit-Queue: Georg Neis <neis@chromium.org>
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#54170}
>
> Bug: v8:7902, v8:7790
> Change-Id: I9cbaf98980379b9b17464af5952ec0c47e1cdc6f
> Reviewed-on: https://chromium-review.googlesource.com/1126999
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54254}

Bug: v8:7902, v8:7790
Change-Id: I2b7a7d186e03990350e375470569177e3309683c
Reviewed-on: https://chromium-review.googlesource.com/1127579
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54280}