gnat compilation fails with missing symbols

[Andreas Jungmaier <ajung@teisa.unican.es>]

Hello all,

in my quest :) for compiling gcc with gnat from the  sources,
I have stumbled across the following message several times,
regardless whether I do this with gcc-2.7.2.1, gcc-2.7.2.3 or 
even gcc-2.8.1, so I am not sure what is going wrong.
In the bind/link part of compilation in the ada-dir, when

gcc  -DIN_GCC   -O2   -o ../gnat1 `cat ../stamp-objlist` b_gnat1.o....

is run, followed by a long list of object files, that pops up:
a-misc.o: In function `yyparse':
a-misc.o(.text+0x16): undefined reference to `__builtin_setjmp'
a-raise.o: In function `__gnat_raise_nodefer_with_msg':
a-raise.o(.text+0xc4): undefined reference to `__builtin_longjmp'      

Now, I have done an nm search in all directories of the distribution,
but, as you may already have guessed, I didn't find what I was looking
for.
The system I am working on is RedHat-5.0, with glibc-2.0.7, gcc-2.7.2.1
from the gnat-3.10p-binary distribution, and I modified the ada
source files 5iosinte.ads/5losinte.ads with the following diff
<    type sigset_t is new unsigned_long;
---
>    type sigset_t is array (1 .. 32) of unsigned_long;
>    pragma Pack (sigset_t);    
as well as a-init.c with
39a40,41
> #define NULL 0
>                    

Any ideas ? 

-------------------------------------------------------------------------
Andreas Jungmaier  		ajung@teisa.unican.es
-------------------------------------------------------------------------