Revert "[SAB] Move Atomics builtins to C++"

src/bootstrapper.h

Index: src/bootstrapper.h
diff --git a/src/bootstrapper.h b/src/bootstrapper.h
index 81acc68afbc3a888cdbe3fe1473550dbfceb291b..81ef396e06b5e2a9dedab4e58f9be116c12bca4e 100644
--- a/src/bootstrapper.h
+++ b/src/bootstrapper.h
@@ -116,6 +116,7 @@ class Bootstrapper final {
                             Handle<String> source, int argc,
                             Handle<Object> argv[], NativesFlag natives_flag);
   static bool CompileBuiltin(Isolate* isolate, int index);
+  static bool CompileExperimentalBuiltin(Isolate* isolate, int index);
   static bool CompileExtraBuiltin(Isolate* isolate, int index);
   static bool CompileExperimentalExtraBuiltin(Isolate* isolate, int index);