Fix some defects identifies by Coverity Prevent. All are false...

src/zone.cc

 // Copyright 2006-2008 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 158 matching lines @@
   if (new_size < kMinimumSegmentSize) {
     new_size = kMinimumSegmentSize;
   } else if (new_size > kMaximumSegmentSize) {
     // Limit the size of new segments to avoid growing the segment size
     // exponentially, thus putting pressure on contiguous virtual address space.
     // All the while making sure to allocate a segment large enough to hold the
     // requested size.
     new_size = Max(kSegmentOverhead + size, kMaximumSegmentSize);
   }
   Segment* segment = Segment::New(new_size);
-  if (segment == NULL) V8::FatalProcessOutOfMemory("Zone");
+  if (segment == NULL) {
+    V8::FatalProcessOutOfMemory("Zone");
+    return NULL;
+  }
 
   // Recompute 'top' and 'limit' based on the new segment.
   Address result = RoundUp(segment->start(), kAlignment);
   position_ = result + size;
   limit_ = segment->end();
   ASSERT(position_ <= limit_);
   return result;
 }
 
 
 } }  // namespace v8::internal