Drop bash 3.2 completion support

This is pretty old at this point, and upstream bash completions project
uses compopt heavily. Completions are by no means a make-or-break
feature anyway, so this is not critical. This basically reverts commit
6f4f9c1b66 made in 2010.

Signed-off-by: Dan McGee <dan@archlinux.org>

contrib/bash_completion.in

@@ -111,18 +111,11 @@ _pacman() {
   true
 }
 
-if [[ $(type -t compopt) = "builtin" ]]; then
-  _pacman_file() {
-    compopt -o filenames; _filedir 'pkg.tar*'
-  }
-  complete -F _pacman -o default pacman
-else
-  _pacman_file() {
-    _filedir 'pkg.tar*'
-  }
-  complete -F _pacman -o filenames -o default pacman
-fi
+_pacman_file() {
+  compopt -o filenames; _filedir 'pkg.tar*'
+}
 
+complete -F _pacman -o default pacman
 complete -F _makepkg -o default makepkg
 complete -F _pacman_key -o default pacman-key