[turbofan] Unify Math.floor / Math.ceil optimization.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 97fa9214f668524e81cd937681923b7ea1a6c1f4..89c66aba3db1362d0bd549410ec2b6df97cc3a02 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -690,8 +690,7 @@ MachineType InstructionSelector::GetMachineType(Node* node) {
     case IrOpcode::kFloat64Div:
     case IrOpcode::kFloat64Mod:
     case IrOpcode::kFloat64Sqrt:
-    case IrOpcode::kFloat64Floor:
-    case IrOpcode::kFloat64Ceil:
+    case IrOpcode::kFloat64RoundDown:
     case IrOpcode::kFloat64RoundTruncate:
     case IrOpcode::kFloat64RoundTiesAway:
       return kMachFloat64;
@@ -901,10 +900,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return VisitFloat64LessThan(node);
     case IrOpcode::kFloat64LessThanOrEqual:
       return VisitFloat64LessThanOrEqual(node);
-    case IrOpcode::kFloat64Floor:
-      return MarkAsDouble(node), VisitFloat64Floor(node);
-    case IrOpcode::kFloat64Ceil:
-      return MarkAsDouble(node), VisitFloat64Ceil(node);
+    case IrOpcode::kFloat64RoundDown:
+      return MarkAsDouble(node), VisitFloat64RoundDown(node);
     case IrOpcode::kFloat64RoundTruncate:
       return MarkAsDouble(node), VisitFloat64RoundTruncate(node);
     case IrOpcode::kFloat64RoundTiesAway: