title: problem with link-time optimization in Xcode
body: <p>Should I turn on "Generate Debug Symbols" in Xcode for release configuration? When it and "Link Time Optimization" are turned on Xcode show warning:</p>
  
  <p><code>
  GenerateDSYMFile build/Release/cocoa_tutorial5.app.dSYM build/Release/cocoa_tutorial5.app/Contents/MacOS/cocoa_tutorial5
  cd /Users/ariel/Documents/spacesimulator.net/cocoa_tutorial5
  /Developer/usr/bin/dsymutil /Users/ariel/Documents/spacesimulator.net/cocoa_tutorial5/build/Release/cocoa_tutorial5.app/Contents/MacOS/cocoa_tutorial5 -o /Users/ariel/Documents/spacesimulator.net/cocoa_tutorial5/build/Release/cocoa_tutorial5.app.dSYM</p>
  
  <p>warning: no debug symbols in executable (-arch x86_64) <br>
  warning: no debug symbols in executable (-arch i386)<br>
  warning: no debug symbols in executable (-arch ppc7400)
  </code></p>