This reverts commit 990dd947.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Introduce HASH_TABLE_TYPE instance type.
> 
> This is so that we can distinguish hash tables by instance type. We can
> then introduce maps for each kind of hash tables to further distinguish.
> 
> R=​mstarzinger@chromium.org
> 
> Bug: v8:6593
> Change-Id: I1a532884758e571abdfe2e2743fc5ea611d12f7e
> Reviewed-on: https://chromium-review.googlesource.com/581009
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46828}

TBR=yangguo@chromium.org,mstarzinger@chromium.org

Change-Id: Ia47d408e5cf47983940227b4cc445a704d7f8d19
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6593
Reviewed-on: https://chromium-review.googlesource.com/581493Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46833}