vim-patch:8.0.0805: GUI test fails with gnome2

Problem:    GUI test fails with gnome2.
Solution:   Set $HOME to an existing directory.
d1ee0043c0

src/nvim/testdir/runtest.vim

@@ -173,6 +173,9 @@ func FinishTesting()
   " Don't write viminfo on exit.
   set viminfo=
 
+  " Clean up files created by setup.vim
+  call delete('XfakeHOME', 'rf')
+
   if s:fail == 0
     " Success, create the .res file so that make knows it's done.
     exe 'split ' . fnamemodify(g:testname, ':r') . '.res'

src/nvim/testdir/setup.vim

@@ -16,7 +16,8 @@ set rtp=$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after
 let &packpath = &rtp
 
 " Make sure $HOME does not get read or written.
-let $HOME = '/does/not/exist'
+let $HOME = getcwd() . '/XfakeHOME'
+call mkdir($HOME)
 
 " Use default shell on Windows to avoid segfault, caused by TUI
 if has('win32')