bpo-30432: FileInput doesn't accept PathLike objects for file names (#1732)

* Allow FileInput to accept a single PathLike object as a parameter for `files`

Fixes

bpo-30432: FileInput doesn't accept PathLike objects for file names

* Address comments from @ambv
diff --git a/Lib/fileinput.py b/Lib/fileinput.py
index 721fe9c..363c241 100644
--- a/Lib/fileinput.py
+++ b/Lib/fileinput.py
@@ -189,6 +189,8 @@
                  mode="r", openhook=None):
         if isinstance(files, str):
             files = (files,)
+        elif isinstance(files, os.PathLike):
+            files = (os.fspath(files), )
         else:
             if files is None:
                 files = sys.argv[1:]