Ada broken on i686-linux

[Arnaud Charlet]

> This can be worked around compiling with -O0, so I'll try a bootstrap with
> everything built at -O0 to see whether I can get at least a successful build
> and commit my pending changes.

Well, I am now hitting the crash already mentioned by Richard and Laurent
on x86_64:

<<
../../xgcc -B../../ -c -g -O0 -fPIC      -W -Wall -gnatpg  a-ncelfu.ads -o a-ncelfu.o
+===========================GNAT BUG DETECTED==============================+
| 3.5.0 20040909 (experimental) (i686-pc-linux-gnu) GCC error:             |
| in optimize_mode_switching, at lcm.c:1225                                |
| Error detected at a-ngelfu.adb:172:16 [a-ngcefu.adb:38:4 [a-ncelfu.ads:19:1]]|>>

Arno