title: {$WARN SYMBOL_PLATFORM OFF} does not turn off warnings
body: <p>I have this piece of code:</p>
  
  <pre><code>INTERFACE
  
  {$WARN SYMBOL_PLATFORM OFF}
  USES
     Winapi.Windows, etc, {$IFDEF MSWINDOWS}Vcl.FileCtrl, {$ENDIF} System.IniFiles;
  {$WARN SYMBOL_PLATFORM ON}
  </code></pre>
  
  <p>The compiler shows:</p>
  
  <blockquote>
    <p>[dcc32 Warning] W1005 Unit 'Vcl.FileCtrl' is
    specific to a platform</p>
  </blockquote>
  
  <p>even though the  {$WARN SYMBOL_PLATFORM OFF} is there.<br>
  Why? </p>