[builtins] Introduce proper Float64Log1p 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 6b042042199a81b698dae757212bd02700ecc12a..d99d2116e820d4272b4cdbd0fdeaec082a12a734 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1129,6 +1129,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsFloat64(node), VisitFloat64Abs(node);
     case IrOpcode::kFloat64Log:
       return MarkAsFloat64(node), VisitFloat64Log(node);
+    case IrOpcode::kFloat64Log1p:
+      return MarkAsFloat64(node), VisitFloat64Log1p(node);
     case IrOpcode::kFloat64Sqrt:
       return MarkAsFloat64(node), VisitFloat64Sqrt(node);
     case IrOpcode::kFloat64Equal:
@@ -1234,6 +1236,14 @@ void InstructionSelector::VisitLoadParentFramePointer(Node* node) {
   Emit(kArchParentFramePointer, g.DefineAsRegister(node));
 }
 
+void InstructionSelector::VisitFloat64Log(Node* node) {
+  VisitFloat64Ieee754Unop(node, kIeee754Float64Log);
+}
+
+void InstructionSelector::VisitFloat64Log1p(Node* node) {
+  VisitFloat64Ieee754Unop(node, kIeee754Float64Log1p);
+}
+
 void InstructionSelector::EmitTableSwitch(const SwitchInfo& sw,
                                           InstructionOperand& index_operand) {
   OperandGenerator g(this);