First implementation of allocation elimination in Hydrogen.

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 718 matching lines @@
   // constructor.  The object is reinitialized and behaves as an
   // object that has been freshly allocated using the constructor.
   MUST_USE_RESULT MaybeObject* ReinitializeJSGlobalProxy(
       JSFunction* constructor, JSGlobalProxy* global);
 
   // Allocates and initializes a new JavaScript object based on a map.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // 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);
 
   // Allocates a heap object based on the map.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // failed.
   // Please note this function does not perform a garbage collection.
   MUST_USE_RESULT MaybeObject* Allocate(Map* map, AllocationSpace space);
 
@@ skipping 2288 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_