Bug#561103: [mips only] gnatbind error: "s-linux.ali" not found, "s-linux.ads" must be compiled

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Aurelien once again saved the day by providing me with his build log.
It did not take me long to notice that s-linux was not compiled at all
on that arch (it is on mipsel).  I patched the mips section in
ada/gcc-interfaces/Makefile.in to make it similar to mipsel and compile
not only s-linux but also mlib-tgt-specific-linux.adb and
indepsw-gnu.adb (in the tools); hopefully this should fix the problem.

I'm building on amd64 now.

-- 
Ludovic Brenta.