patch 8.0.0531: test with long directory name fails on non-unix systems

Problem:    Test with long directory name fails on non-unix systems.
Solution:   Skip the test on non-unix systems.
diff --git a/src/testdir/test_edit.vim b/src/testdir/test_edit.vim
index b43f84b..70e6bea 100644
--- a/src/testdir/test_edit.vim
+++ b/src/testdir/test_edit.vim
@@ -1324,6 +1324,10 @@
 endfunc
 
 func Test_edit_complete_very_long_name()
+  if !has('unix')
+    " Long directory names only work on Unix.
+    return
+  endif
   let save_columns = &columns
   set columns=5000
   call assert_equal(5000, &columns)
diff --git a/src/version.c b/src/version.c
index 16ebc87..56ff4f6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    531,
+/**/
     530,
 /**/
     529,