[heap] Properly propagate allocated space during new space evacuaton in MC

New space evaucation in MC supports, similar to scavenges, fall back allocation
in old space.

For new space evacuation we support stick and non-sticky modes for fallback. The
sticky mode essentially removes the capability to allocate in new space while
the non-sticky mode only falls back for a single allocation.

We use the non-sticky mode for allocations that are too large for a LAB but
should still go in new space. When such an allocation fails in new space, we
allocate in old space in non-sticky mode as we would still like to reuse the
remainder memory in new space. However, in such a case we fail to properly
report the space allocated in resulting in a missed recorded slot.

BUG=chromium:641270
R=ulan@chromium.org

Review-Url: https://codereview.chromium.org/2280943002
Cr-Commit-Position: refs/heads/master@{#38940}

src/heap/mark-compact.cc

@@ -1745,6 +1745,7 @@ class MarkCompactCollector::EvacuateNewSpaceVisitor final
     const int size = old_object->Size();
     AllocationAlignment alignment = old_object->RequiredAlignment();
     AllocationResult allocation;
+    AllocationSpace space_allocated_in = space_to_allocate_;
     if (space_to_allocate_ == NEW_SPACE) {
       if (size > kMaxLabObjectSize) {
         allocation =
@@ -1755,11 +1756,12 @@ class MarkCompactCollector::EvacuateNewSpaceVisitor final
     }
     if (allocation.IsRetry() || (space_to_allocate_ == OLD_SPACE)) {
       allocation = AllocateInOldSpace(size, alignment);
+      space_allocated_in = OLD_SPACE;
     }
     bool ok = allocation.To(target_object);
     DCHECK(ok);
     USE(ok);
-    return space_to_allocate_;
+    return space_allocated_in;
   }
 
   inline bool NewLocalAllocationBuffer() {