[Ada] Fix bootstrap on PowerPC/Linux

[Eric Botcazou]

Something changed recently, probably in the back-end, and this broke bootstrap 
with Ada enabled because the gnattools cannot be linked anymore.

Fixed thusly, bootstrapped/regtested on PowerPC/Linux, applied on the mainline.


2012-05-12  Eric Botcazou  <ebotca...@adacore.com>

        * gcc-interface/Makefile.in (TOOLS_LIBS): Add ../../ggc-none.o.


-- 
Eric Botcazou

with Q; use Q;

package P is

  C : constant R := F;

end P;