The introduction of support for compiling individual files broke the previous behavior of compileall, where it would report that it could not turn a directory name into a file list if the named directory did not exist.

A fix would be to reverse the test used to determine whether or not to call compile_file: instead of calling it if the name is not a directory, we should call it if the name is a file, and pass everything else to compile_dir.  This would restore the previous behaviour.

Note that compileall considers not finding a named file/directory as successful compilation, so this is a low priority bug.