[builtins] Introduce proper Float64Atan and Float64Atan2 operators.

src/compiler/instruction-selector.h

Index: src/compiler/instruction-selector.h
diff --git a/src/compiler/instruction-selector.h b/src/compiler/instruction-selector.h
index b1bcb0fa593bb57eb7dbbc23400695a3f922c09c..8bdbf9b2d9cde3d88477c9e6c38bf9e59d997c63 100644
--- a/src/compiler/instruction-selector.h
+++ b/src/compiler/instruction-selector.h
@@ -245,6 +245,7 @@ class InstructionSelector final {
   void VisitNode(Node* node);
 
   // Visit the node and generate code for IEEE 754 functions.
+  void VisitFloat64Ieee754Binop(Node*, InstructionCode code);
   void VisitFloat64Ieee754Unop(Node*, InstructionCode code);
 
 #define DECLARE_GENERATOR(x) void Visit##x(Node* node);