title: Delphi compiler warnings pointing to Delphi's own units
body: <p>In Delphi 2007, working on a project which includes a custom component, I'm getting this set of warnings as the first four in Messages when I do a full build (but not when I do a straight compile):</p>
  
  <pre><code>[DCC Warning] Dialogs.pas(1426): W1002 Symbol 'TFileOpenDialog' is specific to a platform
  [DCC Warning] Dialogs.pas(1446): W1002 Symbol 'TFileSaveDialog' is specific to a platform
  [DCC Warning] ComCtrls.pas(6757): W1036 Variable 'Section' might not have been initialized
  [DCC Warning] ComCtrls.pas(19268): W1023 Comparing signed and unsigned types - widened both operands
  </code></pre>
  
  <p>I generally try to eliminate compiler warnings where I can, but these are "stock" Delphi units. Are these warnings the indirect result of something in my code?  If so, how do I figure out what/where? If not, what should I do about them?</p>