Revert "[vm,dart2wasm] Move hash factory code to enable sharing of patch files"

This reverts commit 04372ade5e3d1861e3571b705995f35a9f489cd9.

Reason for revert: Flutter PR not rolled into g3 yet.

Original change's description:
> [vm,dart2wasm] Move hash factory code to enable sharing of patch files
>
> By moving the hash map/set factories into their own file, the
> collection_patch and compact_hash patch files can be shared between the
> VM and dart2wasm.
>
> This builds on the preparations from the creation of the file in
> https://dart-review.googlesource.com/c/sdk/+/229905 and listing it in
> the Flutter file lists in https://github.com/flutter/engine/pull/31133.
>
> Change-Id: Ia8f07229af056e59b119008714deecc0c96dd742
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/231947
> Reviewed-by: Daco Harkes <dacoharkes@google.com>
> Commit-Queue: Aske Simon Christensen <askesc@google.com>

TBR=askesc@google.com,dacoharkes@google.com

Change-Id: I6342ef0250cc24b36c4c32e86a4769dbaeffafa4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/232400
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Commit-Queue: Aske Simon Christensen <askesc@google.com>