patch 8.1.0639: text properties test fails on MS-Windows

Problem:    text properties test fails on MS-Windows
Solution:   Set fileformat to "unix".
diff --git a/src/testdir/test_textprop.vim b/src/testdir/test_textprop.vim
index 3ec6ea8..ccf7d28 100644
--- a/src/testdir/test_textprop.vim
+++ b/src/testdir/test_textprop.vim
@@ -230,6 +230,7 @@
   call prop_type_add('comment', {'highlight': 'Directory'})
   new
   call setline(1, ['line1', 'line2', ''])
+  set ff=unix
   call assert_equal(13, line2byte(3))
   call prop_add(1, 1, {'end_col': 3, 'type': 'comment'})
   call assert_equal(13, line2byte(3))
diff --git a/src/version.c b/src/version.c
index 5cffe09..30f2899 100644
--- a/src/version.c
+++ b/src/version.c
@@ -800,6 +800,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    639,
+/**/
     638,
 /**/
     637,