Memory leaks happens in nested anonymous method

In Delphi XE, the following code will cause memory leak:

procedure TForm1.Button1Click(Sender: TObject);
var P, B: TProc;
begin
  B := procedure
       begin
       end;

  P := procedure
       begin
         B;
       end;
end;

Run the code with

ReportMemoryLeaksOnShutdown := True;

and the memory manager prompt:

21-28 bytes: TForm1.Button1Click$ActRec x 1