This reverts commit 3c4bc27f.

Reason for revert: https://bugs.chromium.org/p/chromium/issues/detail?id=770257

Original change's description:
> Reland "[turbofan] eagerly prune None types and deadness from the graph"
> 
> This is a reland of e1cdda25
> Original change's description:
> > [turbofan] eagerly prune None types and deadness from the graph
> > 
> > In addition to using the {Dead} node to prune dead control nodes and nodes that 
> > depend on them, we introduce a {DeadValue} node representing an impossible value 
> > that can occur at any position in the graph. The extended {DeadCodeElimination}
> > prunes {DeadValue} and its uses, inserting a crashing {Unreachable} node into
> > the effect chain when possible. The remaining uses of {DeadValue} are handled
> > in {EffectControlLinearizer}, where we always have access to the effect chain.
> > In addition to explicitly introduced {DeadValue} nodes, we consider any value use
> > of a node with type {None} as dead.
> > 
> > Bug: chromium:741225
> > Change-Id: Icc4b636d1d018c452ba1a2fa7cd3e00e522f1655
> > Reviewed-on: https://chromium-review.googlesource.com/641250
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#48208}
> 
> Bug: chromium:741225
> Change-Id: I21316913dae02864f7a6d7c9269405a79f054138
> Reviewed-on: https://chromium-review.googlesource.com/692034
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48232}

TBR=jarin@chromium.org,tebbi@chromium.org

Change-Id: Ied8da411a9c8cbe4ed2e1d3e98a76162c2834c97
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:741225 chromium:770257
Reviewed-on: https://chromium-review.googlesource.com/693235Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48246}