This reverts commit d9e1f2ae.

Reason for revert: Linux test failures: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux/45960/overview

Original change's description:
> [wasm][liftoff] Spill regs for multi-value merges
>
> If there is more than one value in the merge region, a stack-to-stack
> move can overwrite the source of a stack-to-register move. To avoid
> this, spill all registers.
>
> R=​clemensb@chromium.org
>
> Bug: chromium:1299183
> Change-Id: I10495434d0a18c9072ee3882e00a687edd8c592a
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3523044
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#79584}

Bug: chromium:1299183
Change-Id: I465129695cfc1c5678923f7eefe5b91e31383798
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3546745
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Owners-Override: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79585}