This reverts commit 877de376.

Reason for revert: Looks like this doesn't really move the needle (only w/ high iteration count). So let's not do the extra complexity unless there's a good reason to do so.

Original change's description:
> [turbofan] Introduce FindOrderedHashMapEntryForReceiverKey operator.
> 
> This optimizes Map#get and Map#has for the case where the key is known
> to be a JSReceiver. This generalizes the existing logic for the
> FindOrderedHashMapEntryForSigned32Key operator to also deal with
> receivers. This gives a nice 33% boost on the map-set-lookup-es6 test
> of the six-speed benchmark suite.
> 
> Drive-by-fix: Rename the FindOrderedHashMapEntryForInt32Key operator to
> FindOrderedHashMapEntryForSigned32Key to match the naming of the types.
> 
> R=​jarin@chromium.org
> 
> Bug: v8:5267, v8:7001
> Change-Id: Ifab8414f26adee7ec833d8cb94ae0ac49f2c3d35
> Reviewed-on: https://chromium-review.googlesource.com/738180
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48938}

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

Change-Id: Icaf9e22cb3412a97342c4e4cdc422d4aaa2d0ef9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:5267, v8:7001
Reviewed-on: https://chromium-review.googlesource.com/738052Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48941}