This reverts commit 83d289b8.

Reason for revert: lock order inversion, see https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20TSAN%20-%20isolates/12584/overview

Original change's description:
> Reland [wasm] Reduce job priority once baseline compilation finishes
>
> ReduceCompilationPriority takes a lock now.
>
> Original message:
> This Cl changes the priority of baseline compilation from kUserVisible
> to kUserBlocking. Once baseline compilation finishes, the priority is
> reduced to kUserVisible. The reason for using kUserBlocking is that
> thereby TurboFan compilation cannot block Liftoff compilation anymore.
> Additionally, kUserBlocking is quite appropriate, as the initial
> compilation does block a whole section of a web app from execution.
>
> R=​clemensb@chromium.org
>
> Bug: v8:11088
> Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel_ng
> Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_isolates_rel_ng
> Change-Id: I6e1bcc809148198a4b4f88bfd4f2e62b1b061439
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563675
> Commit-Queue: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71546}

TBR=ahaas@chromium.org,clemensb@chromium.org

Change-Id: I62e4e3d0663dbd181b14f77f0c1586d5e503f324
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:11088
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_isolates_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567953Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71557}