title: Build phase script is running before needed files are created in Xcode 10
body: <p><a href="https://github.com/realm/realm-cocoa/blob/master/scripts/strip-frameworks.sh" rel="nofollow noreferrer">https://github.com/realm/realm-cocoa/blob/master/scripts/strip-frameworks.sh</a></p>
  
  <p>We are always using this script to remove architectures for dynamic frameworks. It has worked with Xcode 9. </p>
  
  <p>In Xcode 10, it didn't remove the architectures.
  Anything in Xcode 10 that could break this?
  We have a theory that it is related to the new build system </p>