First implementation of allocation elimination in Hydrogen.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 41ab43e81b26056df9bf4e0426a147abe43ab56c..a25f8a51c9ae041fb4b35c0792dba5bfccc19f6d 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -736,7 +736,7 @@ class Heap {
   // failed.
   // Please note this does not perform a garbage collection.
   MUST_USE_RESULT MaybeObject* AllocateJSObjectFromMap(
-      Map* map, PretenureFlag pretenure = NOT_TENURED);
+      Map* map, PretenureFlag pretenure = NOT_TENURED, bool alloc_props = true);
 
   MUST_USE_RESULT MaybeObject* AllocateJSObjectFromMapWithAllocationSite(
       Map* map, Handle<AllocationSite> allocation_site);