cc/gcc: disable complibs if not selected

Force gcc to not link with some companion libraries when
there are not needed (because selected-out).

There is no option to tell gcc *not* to build the Graphite and/or
LTO stuff. They *will* be built if gcc finds the suitable companion
libraries. If we do not provide them, but the host has them, then
gcc *will* find them, and link with them.

Consider the following:
- host has suitable PPL and CLooG (eg. Debian Squeeze)
- user wants to build gcc>=4.4
- user de-selects GRAPHITE
- gcc will find the hosts PPL and CLooG, and will use them
- the user moves the toolchain to an older host that does
not have them (eg. Debian Lenny)
- the toolchain fails, when it was properly setup not to

So, explicitly tell gcc *not* to use unneeded companion libs.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

diff -dur libelf-0.8.10.orig/configure libelf-0.8.10/configure

--- libelf-0.8.10.orig/configure	2007-09-07 14:08:06.000000000 +0200

+++ libelf-0.8.10/configure	2008-10-23 22:43:19.000000000 +0200

@@ -1595,7 +1595,7 @@

   echo $ac_n "(cached) $ac_c" 1>&6

 else

   if test "$cross_compiling" = yes; then

-  ac_cv_sizeof_long_long=0

+  ac_cv_sizeof_long_long=8

 else

   cat > conftest.$ac_ext <<EOF

 #line 1602 "configure"

diff -dur libelf-0.8.10.orig/configure.in libelf-0.8.10/configure.in

--- libelf-0.8.10.orig/configure.in	2007-09-07 14:07:59.000000000 +0200

+++ libelf-0.8.10/configure.in	2008-10-23 22:43:10.000000000 +0200

@@ -90,7 +90,7 @@

 AC_CHECK_SIZEOF(short,2)

 AC_CHECK_SIZEOF(int,4)

 AC_CHECK_SIZEOF(long,4)

-AC_CHECK_SIZEOF(long long,0)

+AC_CHECK_SIZEOF(long long,8)

 # Windows port

 AC_CHECK_SIZEOF(__int64, 0)