Fix missing initialization of last_true_block_ in IfBuilder.

src/hydrogen.cc

 // Copyright 2013 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 709 matching lines @@
       finished_(false),
       deopt_then_(false),
       deopt_else_(false),
       did_then_(false),
       did_else_(false),
       did_and_(false),
       did_or_(false),
       captured_(false),
       needs_compare_(false),
       first_true_block_(NULL),
+      last_true_block_(NULL),
       first_false_block_(NULL),
       split_edge_merge_block_(NULL),
       merge_block_(NULL) {
   continuation->Continue(&first_true_block_,
                          &first_false_block_,
                          &position_);
 }
 
 
 void HGraphBuilder::IfBuilder::AddCompare(HControlInstruction* compare) {
@@ skipping 8876 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal