Revert "Eliminatable CheckMaps replaced with if(true) or if(false)."

src/hydrogen-instructions.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 689 matching lines @@
 }
 
 
 void HInstruction::PrintMnemonicTo(StringStream* stream) {
   stream->Add("%s ", Mnemonic());
 }
 
 
 void HInstruction::Unlink() {
   ASSERT(IsLinked());
+  ASSERT(!IsControlInstruction());  // Must never move control instructions.
   ASSERT(!IsBlockEntry());  // Doesn't make sense to delete these.
   ASSERT(previous_ != NULL);
   previous_->next_ = next_;
   if (next_ == NULL) {
     ASSERT(block()->last() == this);
     block()->set_last(previous_);
   } else {
     next_->previous_ = previous_;
   }
   clear_block();
@@ skipping 3710 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal