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>

diff -durN gcc-4.2.1.orig/gcc/Makefile.in gcc-4.2.1/gcc/Makefile.in

--- gcc-4.2.1.orig/gcc/Makefile.in	2007-05-31 17:37:38.000000000 +0200

+++ gcc-4.2.1/gcc/Makefile.in	2007-08-03 20:36:14.000000000 +0200

@@ -2660,7 +2660,7 @@

 # FIXME: writing proper dependencies for this is a *LOT* of work.

 libbackend.o : $(OBJS-common:.o=.c) $(out_file) \

   insn-config.h insn-flags.h insn-codes.h insn-constants.h \

-  insn-attr.h  $(DATESTAMP) $(BASEVER) $(DEVPHASE)

+  insn-attr.h  $(DATESTAMP) $(BASEVER) $(DEVPHASE) gcov-iov.h

 	$(CC) $(ALL_CFLAGS) $(ALL_CPPFLAGS) \

 	  -DTARGET_NAME=\"$(target_noncanonical)\" \

 	  -DLOCALEDIR=\"$(localedir)\" \