AIX: Fix 'may be used uninitialized' compiler errors

src/heap/heap-inl.h

 // 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.
 
 #ifndef V8_HEAP_HEAP_INL_H_
 #define V8_HEAP_HEAP_INL_H_
 
 #include <cmath>
 
 #include "src/base/platform/platform.h"
@@ skipping 108 matching lines @@
 
 AllocationResult Heap::AllocateOneByteInternalizedString(
     Vector<const uint8_t> str, uint32_t hash_field) {
   CHECK_GE(String::kMaxLength, str.length());
   // Compute map and object size.
   Map* map = one_byte_internalized_string_map();
   int size = SeqOneByteString::SizeFor(str.length());
   AllocationSpace space = SelectSpace(size, TENURED);
 
   // Allocate string.
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   // String maps are all immortal immovable objects.
   result->set_map_no_write_barrier(map);
   // Set length and hash fields of the allocated string.
   String* answer = String::cast(result);
   answer->set_length(str.length());
@@ skipping 11 matching lines @@
 
 AllocationResult Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
                                                          uint32_t hash_field) {
   CHECK_GE(String::kMaxLength, str.length());
   // Compute map and object size.
   Map* map = internalized_string_map();
   int size = SeqTwoByteString::SizeFor(str.length());
   AllocationSpace space = SelectSpace(size, TENURED);
 
   // Allocate string.
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   result->set_map(map);
   // Set length and hash fields of the allocated string.
   String* answer = String::cast(result);
   answer->set_length(str.length());
   answer->set_hash_field(hash_field);
@@ skipping 27 matching lines @@
   DCHECK(gc_state_ == NOT_IN_GC);
 #ifdef DEBUG
   if (FLAG_gc_interval >= 0 && AllowAllocationFailure::IsAllowed(isolate_) &&
       Heap::allocation_timeout_-- <= 0) {
     return AllocationResult::Retry(space);
   }
   isolate_->counters()->objs_since_last_full()->Increment();
   isolate_->counters()->objs_since_last_young()->Increment();
 #endif
 
-  HeapObject* object;
+  HeapObject* object = nullptr;
   AllocationResult allocation;
   if (NEW_SPACE == space) {
     allocation = new_space_.AllocateRaw(size_in_bytes, alignment);
     if (always_allocate() && allocation.IsRetry() && retry_space != NEW_SPACE) {
       space = retry_space;
     } else {
       if (allocation.To(&object)) {
         OnAllocationEvent(object, size_in_bytes);
       }
       return allocation;
@@ skipping 564 matching lines @@
 
 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
   for (Object** current = start; current < end; current++) {
     CHECK((*current)->IsSmi());
   }
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_INL_H_