[turbofan] Implemented the optional Float32RoundDown operator.

src/compiler/verifier.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/compiler/verifier.h"
 
 #include <algorithm>
 #include <deque>
 #include <queue>
 #include <sstream>
@@ skipping 870 matching lines @@
     case IrOpcode::kFloat32LessThanOrEqual:
     case IrOpcode::kFloat64Add:
     case IrOpcode::kFloat64Sub:
     case IrOpcode::kFloat64Mul:
     case IrOpcode::kFloat64Div:
     case IrOpcode::kFloat64Mod:
     case IrOpcode::kFloat64Max:
     case IrOpcode::kFloat64Min:
     case IrOpcode::kFloat64Abs:
     case IrOpcode::kFloat64Sqrt:
+    case IrOpcode::kFloat32RoundDown:
     case IrOpcode::kFloat64RoundDown:
     case IrOpcode::kFloat64RoundUp:
     case IrOpcode::kFloat64RoundTruncate:
     case IrOpcode::kFloat64RoundTiesAway:
     case IrOpcode::kFloat64RoundTiesEven:
     case IrOpcode::kFloat64Equal:
     case IrOpcode::kFloat64LessThan:
     case IrOpcode::kFloat64LessThanOrEqual:
     case IrOpcode::kTruncateInt64ToInt32:
     case IrOpcode::kRoundInt64ToFloat32:
@@ skipping 346 matching lines @@
          replacement->op()->EffectOutputCount() > 0);
   DCHECK(!NodeProperties::IsFrameStateEdge(edge) ||
          replacement->opcode() == IrOpcode::kFrameState);
 }
 
 #endif  // DEBUG
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8