Revert of [turbofan] Implemented the TruncateFloat32ToInt64 TurboFan operator.

src/compiler/mips64/instruction-selector-mips64.cc

 // Copyright 2014 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/base/adapters.h"
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 713 matching lines @@
 void InstructionSelector::VisitChangeFloat64ToInt32(Node* node) {
   VisitRR(this, kMips64TruncWD, node);
 }
 
 
 void InstructionSelector::VisitChangeFloat64ToUint32(Node* node) {
   VisitRR(this, kMips64TruncUwD, node);
 }
 
 
-void InstructionSelector::VisitTruncateFloat32ToInt64(Node* node) {
-  VisitRR(this, kMips64TruncLS, node);
-}
-
-
 void InstructionSelector::VisitTruncateFloat64ToInt64(Node* node) {
   VisitRR(this, kMips64TruncLD, node);
 }
 
 
 void InstructionSelector::VisitTruncateFloat64ToUint64(Node* node) {
   VisitRR(this, kMips64TruncUlD, node);
 }
 
 
@@ skipping 849 matching lines @@
          MachineOperatorBuilder::kFloat32Max |
          MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat64RoundUp |
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesEven;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8