Fix compile failure for AIX

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 4438 matching lines @@
   return object;
 }
 
 
 AllocationResult Heap::AllocateConstantPoolArray(
     const ConstantPoolArray::NumberOfEntries& small) {
   CHECK(small.are_in_range(0, ConstantPoolArray::kMaxSmallEntriesPerType));
   int size = ConstantPoolArray::SizeFor(small);
   AllocationSpace space = SelectSpace(size, TENURED);
 
-  HeapObject* object;
+  HeapObject* object = nullptr;
   {
     AllocationResult allocation =
         AllocateRaw(size, space, OLD_SPACE, kDoubleAligned);
     if (!allocation.To(&object)) return allocation;
   }
   object->set_map_no_write_barrier(constant_pool_array_map());
 
   ConstantPoolArray* constant_pool = ConstantPoolArray::cast(object);
   constant_pool->Init(small);
   constant_pool->ClearPtrEntries(isolate());
@@ skipping 2144 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }
 }  // namespace v8::internal