[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

test/cctest/compiler/test-run-machops.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 <cmath>
 #include <functional>
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/base/utils/random-number-generator.h"
@@ skipping 5983 matching lines @@
   m.Return(m.BitcastFloat32ToInt32(
       m.LoadFromPointer(&input, MachineType::Float32())));
   FOR_FLOAT32_INPUTS(i) {
     input = *i;
     int32_t expected = bit_cast<int32_t>(input);
     CHECK_EQ(expected, m.Call());
   }
 }
 
 
+TEST(RunRoundInt32ToFloat32) {
+  BufferedRawMachineAssemblerTester<float> m(MachineType::Int32());
+  m.Return(m.RoundInt32ToFloat32(m.Parameter(0)));
+  FOR_INT32_INPUTS(i) { CHECK_EQ(static_cast<float>(*i), m.Call(*i)); }
+}
+
+
 TEST(RunBitcastInt32ToFloat32) {
   int32_t input = 1;
   float output = 0.0;
   RawMachineAssemblerTester<int32_t> m;
   m.StoreToPointer(
       &output, MachineRepresentation::kFloat32,
       m.BitcastInt32ToFloat32(m.LoadFromPointer(&input, MachineType::Int32())));
   m.Return(m.Int32Constant(11));
   FOR_INT32_INPUTS(i) {
     input = *i;
@@ skipping 50 matching lines @@
   Node* call = r.AddNode(r.common()->Call(desc), phi);
   r.Return(call);
 
   CHECK_EQ(33, r.Call(1));
   CHECK_EQ(44, r.Call(0));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8