Remove buggy ToNumber truncation

src/hydrogen.cc

 // Copyright 2013 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 7661 matching lines @@
 
 
 HValue* HGraphBuilder::TruncateToNumber(HValue* value, Handle<Type>* expected) {
   if (value->IsConstant()) {
     HConstant* constant = HConstant::cast(value);
     Maybe<HConstant*> number = constant->CopyToTruncatedNumber(zone());
     if (number.has_value) {
       *expected = handle(Type::Number(), isolate());
       return AddInstruction(number.value);
     }
-    return value;
-  }
-
-  Handle<Type> expected_type = *expected;
-  Representation rep = Representation::FromType(expected_type);
-  if (!rep.IsTagged()) return value;
-
-  // If our type feedback suggests that we can non-observably truncate to number
-  // we introduce the appropriate check here. This avoids 'value' having a
-  // tagged representation later on.
-  if (expected_type->Is(Type::Oddball())) {
-    // TODO(olivf) The BinaryOpStub only records undefined. It might pay off to
-    // also record booleans and convert them to 0/1 here.
-    IfBuilder if_nan(this);
-    if_nan.If<HCompareObjectEqAndBranch>(value,
-        graph()->GetConstantUndefined());
-    if_nan.Then();
-    if_nan.ElseDeopt();
-    if_nan.End();
-    return Add<HConstant>(OS::nan_value());
   }
 
   return value;
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildBinaryOperation(
     BinaryOperation* expr,
     HValue* left,
     HValue* right) {
@@ skipping 2087 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal