Pass undefined to JS builtins when called with implicit receiver.

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 329fd18dc47cbbde28cd7a16e274d84159cda4e1..9f8d4ba44380ffbabeaa40a977a4c6b9a42984d1 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -131,11 +131,11 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
   }
 #endif
 
-  // Strict mode functions need to replace the receiver with undefined
-  // when called as functions (without an explicit receiver
-  // object). rcx is zero for method calls and non-zero for function
-  // calls.
-  if (info->is_strict_mode()) {
+  // Strict mode functions and builtins need to replace the receiver
+  // with undefined when called as functions (without an explicit
+  // receiver object). rcx is zero for method calls and non-zero for
+  // function calls.
+  if (info->is_strict_mode() || info->is_native()) {
     Label ok;
     __ testq(rcx, rcx);
     __ j(zero, &ok, Label::kNear);