subrepo: run the repo decoders when archiving The decoders were already run by default for the main repo, so this seemed like an oversight. The extdiff extension has been using 'archive' since 68822b7cdd01 to support -S, and a colleague noticed that after diffing, making changes, and closing it, the line endings were wrong for the diff-tool modified files in the subrepository. (Files in the parent repo were correct, with the same .hgeol settings.) The editor (Visual Studio in this case) reloads the file, but doesn't notice the EOL change. It still adds new lines with the original EOL setting, and the file ends up inconsistent. Without this change, the first file `cat`d in the test prints '\r (esc)' EOL, but the second doesn't on Windows or Linux.