Add soft-deopt for uninitialized assignment

src/hydrogen.cc

 // 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 6466 matching lines @@
                                                        name,
                                                        value,
                                                        map));
       }
 
     } else if (types != NULL && types->length() > 1) {
       Drop(2);
       return HandlePolymorphicStoreNamedField(expr, object, value, types, name);
     } else {
       Drop(2);
+      if (expr->IsUninitialized()) {
+        AddSoftDeoptimize();
+      }
       instr = BuildStoreNamedGeneric(object, name, value);
     }
 
     Push(value);
     instr->set_position(expr->position());
     AddInstruction(instr);
     if (instr->HasObservableSideEffects()) {
       AddSimulate(expr->AssignmentId(), REMOVABLE_SIMULATE);
     }
     return ast_context()->ReturnValue(Pop());
@@ skipping 5078 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal