[heap] Sort map space pages in the sweeper

Now that the map space gets compacted as well, we want to sort pages
for that space when starting sweeping as well.

Bug: v8:12578
Change-Id: I8f25fb05f311d70697d2f7154bd428b4c3e56c13
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3455142
Auto-Submit: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79042}

src/heap/sweeper.cc

@@ -165,18 +165,14 @@ void Sweeper::StartSweeping() {
     // evacuating a page, already swept pages will have enough free bytes to
     // hold the objects to move (and therefore, we won't need to wait for more
     // pages to be swept in order to move those objects).
-    // Since maps don't move, there is no need to sort the pages from MAP_SPACE
-    // before sweeping them.
     // We sort in descending order of live bytes, i.e., ascending order of free
     // bytes, because GetSweepingPageSafe returns pages in reverse order.
-    if (space != MAP_SPACE) {
     int space_index = GetSweepSpaceIndex(space);
     std::sort(
-          sweeping_list_[space_index].begin(),
-          sweeping_list_[space_index].end(), [marking_state](Page* a, Page* b) {
+        sweeping_list_[space_index].begin(), sweeping_list_[space_index].end(),
+        [marking_state](Page* a, Page* b) {
           return marking_state->live_bytes(a) > marking_state->live_bytes(b);
         });
-    }
   });
 }