Do not use HNot for creating !bool.

HNot folds to ~, not !.

Change-Id: I681f968449a2ade7110b2f316146ad16ba5da74c
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 49ca443..63bc4ae 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -59,10 +59,9 @@
       equal->ReplaceWith(equal->InputAt(0));
       equal->GetBlock()->RemoveInstruction(equal);
     } else {
-      // Replace (bool_value == 0) with !bool_value
+      // We should replace (bool_value == 0) with !bool_value, but we unfortunately
+      // do not have such instruction.
       DCHECK_EQ(input2->AsIntConstant()->GetValue(), 0);
-      equal->GetBlock()->ReplaceAndRemoveInstructionWith(
-          equal, new (GetGraph()->GetArena()) HNot(Primitive::kPrimBoolean, input1));
     }
   }
 }