Add more Ada testcases

[Eric Botcazou]

> FYI, frame_overflow seems to be failing on x86_64 and ia64-linux:
>
> http://gcc.gnu.org/ml/gcc-testresults/2006-07/msg00481.html
> http://gcc.gnu.org/ml/gcc-testresults/2006-07/msg00425.html
>
> Running target unix
> FAIL: gnat.dg/frame_overflow.adb  (test for errors, line 12)
> FAIL: gnat.dg/frame_overflow.adb  (test for errors, line 21)

Right, known limitation in the DejaGnu machinery for GNAT: the error messages 
should be keyed on "target ilp32" but you get interesting things if you try 
it for the time being. :-)

-- 
Eric Botcazou