[tlbuild] building problems on s390x

[Karl Berry]

Gee, you know this, Norbert ...

1. Report the GCC bug (good luck).
2. Don't use that version of GCC.
3. make CFLAGS="-g -O1"

It's crazy to even begin to try to work around all compiler optimization
bugs, and has been since day one.  I well remember TeX exposing
optimization bugs in GCC 1.x.  (At least those could be reported and
fixed, unlike the ones in vendor compilers.)

karl

P.S. It occurs to me that you might be able to inflict this madness on
yourself if you wish, via something like CFLAGS='`/somescript`' and
having /somescript look at what it is compiling and play around with the
options as desired.  Hopefully possible to get the quoting right, above
is probably insufficient ...