[turbofan] Revert invalid optimization of flooring division.

src/compiler/typed-optimization.cc

 // Copyright 2016 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/compiler/typed-optimization.h"
 
 #include "src/compilation-dependencies.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/simplified-operator.h"
@@ skipping 201 matching lines @@
       //   NumberToUint32(NumberDivide(lhs, rhs))
       //
       // and just smash the type of the {lhs} on the {node},
       // as the truncated result must be in the same range as
       // {lhs} since {rhs} cannot be less than 1 (due to the
       // plain-number type constraint on the {node}).
       NodeProperties::ChangeOp(node, simplified()->NumberToUint32());
       NodeProperties::SetType(node, lhs_type);
       return Changed(node);
     }
-    if (lhs_type->Is(Type::Signed32()) && rhs_type->Is(Type::Unsigned32())) {
-      NodeProperties::ChangeOp(node, simplified()->NumberToInt32());
-      NodeProperties::SetType(node, lhs_type);
-      return Changed(node);
-    }
   }
   return NoChange();
 }
 
 Reduction TypedOptimization::ReduceNumberRoundop(Node* node) {
   Node* const input = NodeProperties::GetValueInput(node, 0);
   Type* const input_type = NodeProperties::GetType(input);
   if (input_type->Is(type_cache_.kIntegerOrMinusZeroOrNaN)) {
     return Replace(input);
   }
@@ skipping 85 matching lines @@
 
 Isolate* TypedOptimization::isolate() const { return jsgraph()->isolate(); }
 
 SimplifiedOperatorBuilder* TypedOptimization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8