scripts: always create lib32 and lib64 symlinks

Unconditionally create the lib32 -> lib/ and lib64 -> lib/ symlinks.

This is reportedly a fix to build a toolchain for a 32-bit target on
a 'pure' 64-bit host (eg. on Fedora FC12, host libs are in lib64/,
and there is no lib -> lib64 symlink, as we can see on other distors,
as Debian). As gcc only puts static host lib in lib64/ (along with
target files in subdirs), we can safely create the symlinks.

Also note that the symlinks are summarily removed at the end
of the build.

Signed-off-by: Anthony Foiani <anthony.foiani@gmail.com>
[Yann E. MORIN: fix a comment, rephrase the commit log]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 Enable using a shell other than bash.

 Courtesy "Martin Guy" <martinwguy@yahoo.it>

 http://sourceware.org/ml/crossgcc/2008-08/msg00037.html

 --- binutils-2.18.orig/ld/genscripts.sh	2007-08-12 20:00:07.000000000 +0100

 +++ binutils-2.18/ld/genscripts.sh	2008-08-25 16:09:54.000000000 +0100

 @@ -398,9 +398,11 @@

      . $em_script

      em_script=$current_script

    }

 -  fragment()

 +  

 +  alias fragment='em_lineno=$LINENO; fragment_em'

 +  fragment_em()

    {

 -    local lineno=$[${BASH_LINENO[0]} + 1]

 +    local lineno=$[$em_lineno + 1]

      echo >> e${EMULATION_NAME}.c "#line $lineno \"$em_script\""

      cat >> e${EMULATION_NAME}.c

    }