[heap] LocalAllocationBuffer needs to use CreateFillerObjectAtBackground

LocalAllocationBuffer is used on the background thread so it needs
to use CreateFillerObjectAtBackground for creating filler objects.

Bug: v8:10315
Change-Id: Ifc22d87e1e835cfdd65d82fc79b20ee74b2c87b1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2336795Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69224}

src/heap/spaces.cc

@@ -314,10 +314,10 @@ LinearAllocationArea LocalAllocationBuffer::CloseAndMakeIterable() {
 
 void LocalAllocationBuffer::MakeIterable() {
   if (IsValid()) {
-    heap_->CreateFillerObjectAt(
+    heap_->CreateFillerObjectAtBackground(
         allocation_info_.top(),
         static_cast<int>(allocation_info_.limit() - allocation_info_.top()),
-        ClearRecordedSlots::kNo);
+        ClearFreedMemoryMode::kDontClearFreedMemory);
   }
 }
 
@@ -326,10 +326,10 @@ LocalAllocationBuffer::LocalAllocationBuffer(
     : heap_(heap),
       allocation_info_(allocation_info) {
   if (IsValid()) {
-    heap_->CreateFillerObjectAt(
+    heap_->CreateFillerObjectAtBackground(
         allocation_info_.top(),
         static_cast<int>(allocation_info_.limit() - allocation_info_.top()),
-        ClearRecordedSlots::kNo);
+        ClearFreedMemoryMode::kDontClearFreedMemory);
   }
 }