Fix an assertion failure in stack trace construction.

src/hydrogen.cc

 // Copyright 2011 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 852 matching lines @@
         }
       }
       // Replace the uses and add phis modified to the work list.
       for (int i = 0; i < uses_to_replace.length(); ++i) {
         HValue* use = uses_to_replace[i];
         phi->ReplaceAtUse(use, value);
         if (use->IsPhi()) worklist.Add(HPhi::cast(use));
       }
       uses_to_replace.Rewind(0);
       block->RemovePhi(phi);
-    } else if (phi->HasNoUses() &&
-               !phi->HasReceiverOperand() &&
-               FLAG_eliminate_dead_phis) {
-      // We can't eliminate phis that have the receiver as an operand
-      // because in case of throwing an error we need the correct
-      // receiver value in the environment to construct a corrent
-      // stack trace.
+    } else if (FLAG_eliminate_dead_phis && phi->HasNoUses() &&
+               !phi->IsReceiver()) {
+      // We can't eliminate phis in the receiver position in the environment
+      // because in case of throwing an error we need this value to
+      // construct a stack trace.
       block->RemovePhi(phi);
       block->RecordDeletedPhi(phi->merged_index());
     }
   }
 }
 
 
 bool HGraph::CollectPhis() {
   const ZoneList<HBasicBlock*>* blocks = graph_->blocks();
   phi_list_ = new ZoneList<HPhi*>(blocks->length());
@@ skipping 5038 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal