[rwx][mac] Add missing scopes in ConcurrentAllocator

Bug: v8:12797
Change-Id: Ide50026c7dc35197876e66cc53a7936acb765aa9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3687735
Auto-Submit: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80965}

src/heap/concurrent-allocator.cc

@@ -102,6 +102,11 @@ void ConcurrentAllocator::MarkLinearAllocationAreaBlack() {
   Address limit = lab_.limit();
 
   if (top != kNullAddress && top != limit) {
+    base::Optional<CodePageHeaderModificationScope> optional_rwx_write_scope;
+    if (space_->identity() == CODE_SPACE) {
+      optional_rwx_write_scope.emplace(
+          "Marking Code objects requires write access to the Code page header");
+    }
     Page::FromAllocationAreaAddress(top)->CreateBlackAreaBackground(top, limit);
   }
 }
@@ -111,6 +116,11 @@ void ConcurrentAllocator::UnmarkLinearAllocationArea() {
   Address limit = lab_.limit();
 
   if (top != kNullAddress && top != limit) {
+    base::Optional<CodePageHeaderModificationScope> optional_rwx_write_scope;
+    if (space_->identity() == CODE_SPACE) {
+      optional_rwx_write_scope.emplace(
+          "Marking Code objects requires write access to the Code page header");
+    }
     Page::FromAllocationAreaAddress(top)->DestroyBlackAreaBackground(top,
                                                                      limit);
   }