Rebuilding the RTL : Makefile.adalib?

[Brian Drummond <brian_drummond@btconnect.com>]

Trying to get an Ada plugin working in Eclipse, I came across Gnatbench
[3 below]. which apparently requires rebuilding the runtime library to
build, and a Makefile that appears to be missing from my distribution.

"It may be useful to recompile the GNAT library in various contexts,
[...] A special Makefile called Makefile.adalib is provided to that
effect and can be found in the directory containing the GNAT library
[1]"

Recently installed openSuse 11, with Gnat 4.3.1, and Makefile.adalib is
not there. 

Downloaded gcc-ada-4.3.1.tar.bz2 from 
ftp://ftp.mirrorservice.org/sites/sourceware.org/pub/gcc/releases/gcc-4.3.1/
which doesn't have it either; either in the /adalib or /gcc/ada. 

Do I need to rebuild GCC and Gnat from sources to regenerate it? Or is
there somewhere else can I obtain it?

A web search only finds it in 3.xx versions, yet [2] shows it in use as
late as last November, and Gnatbench 2.1.0 from [3] requires it, so I
presume it isn't obsolete.

- Brian

[1]
http://gcc.gnu.org/onlinedocs/gnat_ugn_unw/Rebuilding-the-GNAT-Run_002dTime-Library.html

[2]
http://coding.derkeiler.com/Archive/Ada/comp.lang.ada/2007-11/msg00459.html

[3]
https://gforge.enseeiht.fr/projects/gnatbench