Fix --with-system-readline with readline-6.3 patch 5

Fix --with-system-readline with readline-6.3 patch 5

I have filed now:
	--with-system-readline uses bundled readline include files
	https://sourceware.org/bugzilla/show_bug.cgi?id=17077

To see any effect of the patch below you have to do:
	rm -rf readline
Otherwise readline include files get used the bundled ones from GDB which are
currently 6.2 while system readline may be 6.3 already.

You also have to use system readline-6.3 including its upstream patch:
	[Bug-readline] Readline-6.3 Official Patch 5
	http://lists.gnu.org/archive/html/bug-readline/2014-04/msg00018.html
	Message-ID: <140415125618.AA57598.SM@caleb.ins.cwru.edu>

In short it happens on Fedora Rawhide since:
	readline-6.3-1.fc21
	https://koji.fedoraproject.org/koji/buildinfo?buildID=538941

The error is:
	../../gdb/tui/tui-io.c:132:1: error: 'Function' is deprecated [-Werror=deprecated-declarations]
	 static Function *tui_old_rl_getc_function;
	 ^
	../../gdb/tui/tui-io.c:133:1: error: 'VFunction' is deprecated [-Werror=deprecated-declarations]
	 static VFunction *tui_old_rl_redisplay_function;
	 ^
	../../gdb/tui/tui-io.c:134:1: error: 'VFunction' is deprecated [-Werror=deprecated-declarations]
	 static VFunction *tui_old_rl_prep_terminal;
	 ^
	../../gdb/tui/tui-io.c:135:1: error: 'VFunction' is deprecated [-Werror=deprecated-declarations]
	 static VFunction *tui_old_rl_deprep_terminal;
	 ^

It is since bash change:
lib/readline/rltypedefs.h
       - remove old Function/VFunction/CPFunction/CPPFunction typedefs as
	 suggested by Tom Tromey <tromey@redhat.com>

The new typedefs used below are present in readline/rltypedefs.h since:
	git://git.savannah.gnu.org/bash.git
	commit 28ef6c316f1aff914bb95ac09787a3c83c1815fd
	Date:   Fri Apr 6 19:14:31 2001 +0000

gdb/
2014-06-20  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix --with-system-readline with readline-6.3 patch 5.
	* tui/tui-io.c (tui_old_rl_getc_function, tui_old_rl_redisplay_function)
	(tui_old_rl_prep_terminal, tui_old_rl_deprep_terminal): Use rl_*_t
	types.

Message-ID: <20140620105004.GA22236@host2.jankratochvil.net>