Fix IfBuilder::Deopt to clear the current block.

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 794 matching lines @@
   last_true_block_ = builder_->current_block();
   ASSERT(first_true_block_ == NULL || !last_true_block_->IsFinished());
   builder_->set_current_block(first_false_block_);
   did_else_ = true;
 }
 
 
 void HGraphBuilder::IfBuilder::Deopt() {
   HBasicBlock* block = builder_->current_block();
   block->FinishExitWithDeoptimization(HDeoptimize::kUseAll);
+  builder_->set_current_block(NULL);
   if (did_else_) {
     first_false_block_ = NULL;
   } else {
     first_true_block_ = NULL;
   }
 }
 
 
 void HGraphBuilder::IfBuilder::Return(HValue* value) {
   HBasicBlock* block = builder_->current_block();
@@ skipping 6362 matching lines @@
       if (IsExternalArrayElementsKind(map->elements_kind())) {
         todo_external_array = true;
       }
       num_untransitionable_maps++;
       untransitionable_map = map;
     }
   }
 
   // If only one map is left after transitioning, handle this case
   // monomorphically.
+  ASSERT(num_untransitionable_maps >= 1);
   if (num_untransitionable_maps == 1) {
     HInstruction* instr = NULL;
     if (untransitionable_map->has_slow_elements_kind()) {
       instr = AddInstruction(is_store ? BuildStoreKeyedGeneric(object, key, val)
                                       : BuildLoadKeyedGeneric(object, key));
     } else {
       instr = BuildMonomorphicElementAccess(
           object, key, val, transition, untransitionable_map, is_store,
           store_mode);
     }
@@ skipping 4265 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal