Info-goto-node cannot find the "Top" node for some Info files
generated with makeinfo 5.1.

I've attached a minimal example of a Texinfo file where it fails.
To reproduce, save attached file as "test.texi".

   $ makeinfo --version
   makeinfo (GNU texinfo) 5.1
   [...]
   $ makeinfo --split-size=2000 test.texi
   $ ls -l test.info*
   -rw-r--r-- 1 ulm users  221 Apr  2 18:43 test.info
   -rw-r--r-- 1 ulm users 3017 Apr  2 18:43 test.info-1
   -rw-r--r-- 1 ulm users 1509 Apr  2 18:43 test.info-2
   $ emacs -Q
   C-h i
   g (/path/to/test.info) RET

The last command fails with an error: "No such node or anchor: Top"

The bug is not triggered if I use makeinfo 4.13 to create the Info
file from the same Texinfo source.

Not entirely sure if the problem is in Emacs or in makeinfo. I report
it here because standalone info (version 4.13 or 5.1) has no problem
with the files.

In GNU Emacs 24.3.1 (x86_64-pc-linux-gnu, X toolkit)
 of 2013-03-26 on a1i15
Windowing system distributor `The X.Org Foundation', version 11.0.11400000
System Description:	Gentoo Base System release 2.2