bootstrap failure current CVS in Ada

[Daniel Berlin]

> It fails in a different place - here:
>
> stage1/xgcc -Bstage1/ -B/opt/gcc/4.0-devel/x86_64-suse-linux-gnu/bin/ -c -g -O2     -gnatpg -gnata -I- -I. -Iada -I/cvs/gcc/gcc/ada /cvs/gcc/gcc/ada/exp_ch2.adb -o ada/exp_ch2.o
> +===========================GNAT BUG DETECTED==============================+
> | 4.0.0 20050105 (experimental) (x86_64-suse-linux-gnu) GCC error:         |
> | in add_abstract_origin_attribute, at dwarf2out.c:10465                   |

This part is the same as the java error (IE it means the block tree is 
either incorrect or not marked used properly before lowering).
The debug writers expect that a block is marked used if either their are 
used variables *or* the subblocks are used.  This problem only hits if a 
function is inlined but never makes it through lowering, because lowering 
the function fixes up the block tree already.

I've got a workaround for this i plan on submitting in a few moments 
that just tells it to stop trying to output debug info for the inlined 
thing in this case, because fixing the frontends (particularly java) 
is a bit too invasive for 4.0.  This whole thing is "fixed" on 
tree-profiling-branch anyway, which is planned to be submitted for 
4.1, and it lowers the functions before inlining, so we never hit this problem.

This only affects optimizing code debugging, and even then, we are already 
producing better debug info than we did before.

--Dan