The combination of --wasm-write-protect-code-memory and MAP_JIT was not
handled correctly. We were trying to unnecessarily switch permissions,
and a DCHECK was failing because the writers count was not increased
previously (because the {CodeSpaceWriteScope} uses a separate
implementation if MAP_JIT is available).

This CL fixes the issues by explicitly setting
{WasmCodeAllocator::protect_code_memory_} to false if MAP_JIT is being
used.

R=jkummerow@chromium.org

Bug: v8:12070
Change-Id: Ifb05ba01f8e2e7781d7c29fe80d1144a3d65543b
Cq-Include-Trybots: luci.v8.try:v8_mac_arm64_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_mac_arm64_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3089159Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76233}