Add and fix tests from upstream vim

indent/xf86conf.vim

@@ -0,0 +1,41 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'xf86conf') == -1
+
+" Vim indent file
+" Language:             XFree86 Configuration File
+" Previous Maintainer:  Nikolai Weibull <now@bitwi.se>
+" Latest Revision:      2006-12-20
+
+if exists("b:did_indent")
+  finish
+endif
+let b:did_indent = 1
+
+setlocal indentexpr=GetXF86ConfIndent()
+setlocal indentkeys=!^F,o,O,=End
+setlocal nosmartindent
+
+if exists("*GetXF86ConfIndent")
+  finish
+endif
+
+function GetXF86ConfIndent()
+  let lnum = prevnonblank(v:lnum - 1)
+
+  if lnum == 0
+    return 0
+  endif
+
+  let ind = indent(lnum)
+
+  if getline(lnum) =~? '^\s*\(Sub\)\=Section\>'
+    let ind = ind + shiftwidth()
+  endif
+
+  if getline(v:lnum) =~? '^\s*End\(Sub\)\=Section\>'
+    let ind = ind - shiftwidth()
+  endif
+
+  return ind
+endfunction
+
+endif