[builtins] Introduce proper Float64Atan and Float64Atan2 operators.

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index b87178a2e4946035ae374c0557e5f5b65c1dfa0a..1dd3b8441f9643fc6849de23645f023f8913f29e 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -1408,6 +1408,14 @@ void InstructionSelector::VisitFloat32Neg(Node* node) { UNREACHABLE(); }
 
 void InstructionSelector::VisitFloat64Neg(Node* node) { UNREACHABLE(); }
 
+void InstructionSelector::VisitFloat64Ieee754Binop(Node* node,
+                                                   InstructionCode opcode) {
+  X64OperandGenerator g(this);
+  Emit(opcode, g.DefineAsFixed(node, xmm0), g.UseFixed(node->InputAt(0), xmm0),
+       g.UseFixed(node->InputAt(1), xmm1))
+      ->MarkAsCall();
+}
+
 void InstructionSelector::VisitFloat64Ieee754Unop(Node* node,
                                                   InstructionCode opcode) {
   X64OperandGenerator g(this);