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>

--- gcc-4.2.1-stock/gcc/config/alpha/linux-unwind.h	2005-06-24 20:22:41.000000000 -0500

+++ gcc-4.2.1/gcc/config/alpha/linux-unwind.h	2007-09-01 20:21:34.000000000 -0500

@@ -29,6 +29,9 @@ Boston, MA 02110-1301, USA.  */

 /* Do code reading to identify a signal frame, and set the frame

    state data appropriately.  See unwind-dw2.c for the structs.  */

+/* Don't use this if inhibit_libc is set

+   The build for this target will fail trying to include missing headers */

+#ifndef inhibit_libc

 #include <signal.h>

 #include <sys/ucontext.h>

@@ -80,3 +83,4 @@ alpha_fallback_frame_state (struct _Unwi

   fs->retaddr_column = 64;

   return _URC_NO_REASON;

 }

+#endif /* inhibit_libc */