This reverts commit 74c68e2a.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20UBSan/21353/overview

Original change's description:
> [heap] Disable map space with --future
>
> Original CL got reverted, this time the failing test should be fixed.
>
> Bug: v8:12578
> Change-Id: Id2d8801f07742e8b00884fefec8200e4270f4250
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3657434
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#80668}

Bug: v8:12578
Change-Id: I2ee20c79ec09ff4f7bece6ddcc1c3a5cd9351223
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3647692
Owners-Override: Tobias Tebbi <tebbi@chromium.org>
Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#80669}