[heap] Move to page lookups for SemiSpace, NewSpace, and Heap containment methods

src/heap/slots-buffer.cc

Index: src/heap/slots-buffer.cc
diff --git a/src/heap/slots-buffer.cc b/src/heap/slots-buffer.cc
index 3f145e6e2e809b82ba286a4c99e3e78e32584c37..5a3db281fda576180de0b76d8468e3f21d5fe345 100644
--- a/src/heap/slots-buffer.cc
+++ b/src/heap/slots-buffer.cc
@@ -56,9 +56,12 @@ void SlotsBuffer::RemoveInvalidSlots(Heap* heap, SlotsBuffer* buffer) {
         // - point to a heap object in new space
         // - are not within a live heap object on a valid pointer slot
         // - point to a heap object not on an evacuation candidate
-        if (!object->IsHeapObject() || heap->InNewSpace(object) ||
+        // TODO(mlippautz): Move InNewSpace check above IsSlotInLiveObject once
+        //   we filter out unboxed double slots eagerly.
+        if (!object->IsHeapObject() ||
             !heap->mark_compact_collector()->IsSlotInLiveObject(
                 reinterpret_cast<Address>(slot)) ||
+            heap->InNewSpace(object) ||
             !Page::FromAddress(reinterpret_cast<Address>(object))
                  ->IsEvacuationCandidate()) {
           // TODO(hpayer): Instead of replacing slots with kRemovedEntry we