Refactor space bitmap to be a value object

Remove the need for pointer indirections at many places, reduce the
amount of code.

Bug: 116052292
Test: test-art-host
Change-Id: I4b1040d29f9ba99ea23c51f70a06af2ffbe496d4
diff --git a/runtime/gc/space/dlmalloc_space.cc b/runtime/gc/space/dlmalloc_space.cc
index 3ef0f4e..3fa4c3c 100644
--- a/runtime/gc/space/dlmalloc_space.cc
+++ b/runtime/gc/space/dlmalloc_space.cc
@@ -337,8 +337,8 @@
 void DlMallocSpace::Clear() {
   size_t footprint_limit = GetFootprintLimit();
   madvise(GetMemMap()->Begin(), GetMemMap()->Size(), MADV_DONTNEED);
-  live_bitmap_->Clear();
-  mark_bitmap_->Clear();
+  live_bitmap_.Clear();
+  mark_bitmap_.Clear();
   SetEnd(Begin() + starting_size_);
   mspace_ = CreateMspace(mem_map_.Begin(), starting_size_, initial_size_);
   SetFootprintLimit(footprint_limit);