debug/gdb: install gdbinit sample file

gdb needs to know where to find the libstdc++ helper python script
to do, well, whatever it has to do with it...

We can't install that in the user's ~/.gdbinit, it's too complex to
handle all the cases. Moreover, if the user is using more than one
toolchain, we can't put all that stuff in there...

Just provide a sample config file the user can adapt to his/her
own needs.

Thanks go to Khem RAJ for providing such a hint:
http://sourceware.org/ml/crossgcc/2011-07/msg00026.html

Reported-by: ANDY KENNEDY <ANDY.KENNEDY@adtran.com>
CC: Khem Raj <raj.khem@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

#!/bin/sh

SKIP_ME="### CT_NG SKIP ME ###"

skip_me=$(($(cat "${0}" |@@grep@@ --binary-files=text -o -b -E "^${SKIP_ME}$" |cut -d : -f 1)+${#SKIP_ME}+1))

dd if="${0}" bs=${skip_me} skip=1 2>/dev/null |bzcat

exit 0

### CT_NG SKIP ME ###