[turbofan] Desugar JSUnaryNot(x) to Select(x, false, true).

src/ic/ic.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ic/ic.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 2795 matching lines @@
   CHECK(false);
   return isolate->heap()->undefined_value();
 }
 
 
 Handle<Object> ToBooleanIC::ToBoolean(Handle<Object> object) {
   ToBooleanStub stub(isolate(), target()->extra_ic_state());
   bool to_boolean_value = stub.UpdateStatus(object);
   Handle<Code> code = stub.GetCode();
   set_target(*code);
-  return handle(Smi::FromInt(to_boolean_value ? 1 : 0), isolate());
+  return isolate()->factory()->ToBoolean(to_boolean_value);
 }
 
 
 RUNTIME_FUNCTION(Runtime_ToBooleanIC_Miss) {
   TimerEventScope<TimerEventIcMiss> timer(isolate);
   DCHECK(args.length() == 1);
   HandleScope scope(isolate);
   Handle<Object> object = args.at<Object>(0);
   ToBooleanIC ic(isolate);
   return *ic.ToBoolean(object);
@@ skipping 163 matching lines @@
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   }
 
   return *result;
 }
 }  // namespace internal
 }  // namespace v8