[turbofan] Implemented the optional Float32RoundDown operator.

src/compiler/raw-machine-assembler.h

 // 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.
 
 #ifndef V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 #define V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 
 #include "src/assembler.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
@@ skipping 465 matching lines @@
   }
   Node* BitcastFloat64ToInt64(Node* a) {
     return AddNode(machine()->BitcastFloat64ToInt64(), a);
   }
   Node* BitcastInt32ToFloat32(Node* a) {
     return AddNode(machine()->BitcastInt32ToFloat32(), a);
   }
   Node* BitcastInt64ToFloat64(Node* a) {
     return AddNode(machine()->BitcastInt64ToFloat64(), a);
   }
+  Node* Float32RoundDown(Node* a) {
+    return AddNode(machine()->Float32RoundDown().op(), a);
+  }
   Node* Float64RoundDown(Node* a) {
     return AddNode(machine()->Float64RoundDown().op(), a);
   }
   Node* Float64RoundUp(Node* a) {
     return AddNode(machine()->Float64RoundUp().op(), a);
   }
   Node* Float64RoundTruncate(Node* a) {
     return AddNode(machine()->Float64RoundTruncate().op(), a);
   }
   Node* Float64RoundTiesAway(Node* a) {
@@ skipping 133 matching lines @@
   BasicBlock* current_block_;
 
   DISALLOW_COPY_AND_ASSIGN(RawMachineAssembler);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_