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>

This is the README for crosstool-NG

Crosstool-NG follows the autoconf dance. So, to get you

kick-started, just run:

  ./configure --help

You will find the documentation in the directory 'docs'.

Here is a quick overview of what you'll find there:

  0 - Table of content

  1 - Introduction

  2 - Installing crosstool-NG

  3 - Configuring a toolchain

  4 - Building the toolchain

  5 - Using the toolchain

  6 - Toolchain types

  7 - Contributing

  8 - Internals

  A - Credits

  B - Known issues

  C - Misc. tutorials

You can also point your browser at:

  http://ymorin.is-a-geek.org/projects/crosstool

Aloha!