[builtins] Introduce proper Float64Tan operator.

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 4c1387a6aabd107f491e33d430bbdcdb217f82b5..558aff3b6cdb093930293a33d2287e4d047157f5 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1160,6 +1160,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsFloat64(node), VisitFloat64Sin(node);
     case IrOpcode::kFloat64Sqrt:
       return MarkAsFloat64(node), VisitFloat64Sqrt(node);
+    case IrOpcode::kFloat64Tan:
+      return MarkAsFloat64(node), VisitFloat64Tan(node);
     case IrOpcode::kFloat64Equal:
       return VisitFloat64Equal(node);
     case IrOpcode::kFloat64LessThan:
@@ -1311,6 +1313,10 @@ void InstructionSelector::VisitFloat64Sin(Node* node) {
   VisitFloat64Ieee754Unop(node, kIeee754Float64Sin);
 }
 
+void InstructionSelector::VisitFloat64Tan(Node* node) {
+  VisitFloat64Ieee754Unop(node, kIeee754Float64Tan);
+}
+
 void InstructionSelector::EmitTableSwitch(const SwitchInfo& sw,
                                           InstructionOperand& index_operand) {
   OperandGenerator g(this);