message: Change sort-pbxproj.rb to find the project.pbxproj in the
  most likely locations.  And have it overwrite the original
  file with the sorted output.
diff: # can lead to merge failures.
  segregated_filenames = ["Swift", "repl", "RPC"]
  -if !File.exists?("project.pbxproj")
  - STDERR.puts "ERROR: project.pbxproj does not exist."
  - exit(1)
  -end
  -
  def read_pbxproj(fn)
  beginning = Array.new # All lines before "PBXBuildFile section"
  files = Array.new # PBXBuildFile section lines -- sort these
  @@ -74,7 +69,20 @@ def read_pbxproj(fn)
  return beginning, files, middle, refs, ending
  end
  -beginning, files, middle, refs, ending = read_pbxproj("project.pbxproj")
  +xcodeproj_filename = nil
  +[ "../lldb.xcodeproj/project.pbxproj", "lldb.xcodeproj/project.pbxproj", "project.pbxproj" ].each do |ent|
  + if File.exists?(ent)
  + xcodeproj_filename = ent
  + break
  + end
  +end
  +
  +if xcodeproj_filename.nil?
  + STDERR.puts "Could not find xcode project file to sort."
  + exit(1)
  +end
  +
  +beginning, files, middle, refs, ending = read_pbxproj(xcodeproj_filename)
  ### If we're given a "canonical" project.pbxproj file, get the uuid and fileref ids for
  @@ -236,6 +244,8 @@ end
  ####### output the sorted pbxproj
  +File.open(xcodeproj_filename, 'w') do |outfile|
  [ beginning, files, middle, refs, ending ].each do |arr|
  - arr.each {|l| puts l}
  + arr.each {|l| outfile.puts l}
  + end
  end
  