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 -durN gcc-4.3.2.orig/libgcc/config/sh/t-linux gcc-4.3.2/libgcc/config/sh/t-linux

 --- gcc-4.3.2.orig/libgcc/config/sh/t-linux	2009-03-07 11:42:38.000000000 +0100

 +++ gcc-4.3.2/libgcc/config/sh/t-linux	2009-03-07 11:03:39.000000000 +0100

 @@ -15,7 +15,7 @@

  	-Wl,--soname=@shlib_base_name@.so.1 \

  	-Wl,--version-script=@shlib_map_file@ \

  	-o @multilib_dir@/@shlib_base_name@.so.1.tmp @multilib_flags@ \

 -	@shlib_objs@ -lc && \

 +	@shlib_objs@ && \

  	rm -f @multilib_dir@/@shlib_base_name@.so && \

  	if [ -f @multilib_dir@/@shlib_base_name@.so.1 ]; then \

  	  mv -f @multilib_dir@/@shlib_base_name@.so.1 \