[turbofan] Add TruncateFloat64ToInt32 machine operator.

src/compiler/machine-operator.h

 // Copyright 2013 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.
 
 #ifndef V8_COMPILER_MACHINE_OPERATOR_H_
 #define V8_COMPILER_MACHINE_OPERATOR_H_
 
 #include "src/compiler/machine-type.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
@@ skipping 116 matching lines @@
   // integers.
   Operator* ChangeInt32ToFloat64() { UNOP(ChangeInt32ToFloat64); }
   Operator* ChangeUint32ToFloat64() { UNOP(ChangeUint32ToFloat64); }
   Operator* ChangeFloat64ToInt32() { UNOP(ChangeFloat64ToInt32); }
   Operator* ChangeFloat64ToUint32() { UNOP(ChangeFloat64ToUint32); }
 
   // Sign/zero extend int32/uint32 to int64/uint64.
   Operator* ChangeInt32ToInt64() { UNOP(ChangeInt32ToInt64); }
   Operator* ChangeUint32ToUint64() { UNOP(ChangeUint32ToUint64); }
 
+  // Truncate double to int32 using JavaScript semantics.
+  Operator* TruncateFloat64ToInt32() { UNOP(TruncateFloat64ToInt32); }
+
   // Truncate the high order bits and convert the remaining bits to int32.
   Operator* TruncateInt64ToInt32() { UNOP(TruncateInt64ToInt32); }
 
   // Floating point operators always operate with IEEE 754 round-to-nearest.
   Operator* Float64Add() { BINOP_C(Float64Add); }
   Operator* Float64Sub() { BINOP(Float64Sub); }
   Operator* Float64Mul() { BINOP_C(Float64Mul); }
   Operator* Float64Div() { BINOP(Float64Div); }
   Operator* Float64Mod() { BINOP(Float64Mod); }
 
@@ skipping 18 matching lines @@
 
  private:
   Zone* zone_;
   MachineType word_;
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_MACHINE_OPERATOR_H_