Add field nested_sites to AllocationSite.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 4ee437214b61ba630d6f87ac204fecda7e7ae01a..c0ce58080be06fd967a23960cf5d0041c832fc47 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1325,6 +1325,7 @@ bool JSObject::ShouldTrackAllocationInfo() {
 
 void AllocationSite::Initialize() {
   SetElementsKind(GetInitialFastElementsKind());
+  set_nested_site(Smi::FromInt(0));
   set_dependent_code(DependentCode::cast(GetHeap()->empty_fixed_array()),
                      SKIP_WRITE_BARRIER);
 }
@@ -4487,6 +4488,7 @@ ACCESSORS(SignatureInfo, args, Object, kArgsOffset)
 ACCESSORS(TypeSwitchInfo, types, Object, kTypesOffset)
 
 ACCESSORS(AllocationSite, transition_info, Object, kTransitionInfoOffset)
+ACCESSORS(AllocationSite, nested_site, Object, kNestedSiteOffset)
 ACCESSORS(AllocationSite, dependent_code, DependentCode,
           kDependentCodeOffset)
 ACCESSORS(AllocationSite, weak_next, Object, kWeakNextOffset)