heap: Fix compaction aborting all pages

In such a case, we must post-process all aborted pages. The early
bailout assumed that not pages are aborted before trying compaction.

Bug: chromium:1271229
Change-Id: I4c5998b9d1c7974f7d1d25a6729f42d5690a5759
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3289171Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77987}

src/heap/mark-compact.cc

@@ -3606,16 +3606,16 @@ void MarkCompactCollector::EvacuatePagesInParallel() {
     }
   }
 
-  if (evacuation_items.empty()) return;
-
-  TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
-               "MarkCompactCollector::EvacuatePagesInParallel", "pages",
-               evacuation_items.size());
-
   const size_t pages_count = evacuation_items.size();
-  const size_t wanted_num_tasks =
-      CreateAndExecuteEvacuationTasks<FullEvacuator>(
-          this, std::move(evacuation_items), nullptr);
+  size_t wanted_num_tasks = 0;
+  if (!evacuation_items.empty()) {
+    TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
+                 "MarkCompactCollector::EvacuatePagesInParallel", "pages",
+                 evacuation_items.size());
+
+    wanted_num_tasks = CreateAndExecuteEvacuationTasks<FullEvacuator>(
+        this, std::move(evacuation_items), nullptr);
+  }
 
   // After evacuation there might still be swept pages that weren't
   // added to one of the compaction space but still reside in the