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-4.4.0.orig/gcc/configure gcc-4.4.0/gcc/configure

 --- gcc-4.4.0.orig/gcc/configure	2009-05-27 21:38:08.000000000 +0200

 +++ gcc-4.4.0/gcc/configure	2009-05-27 21:38:42.000000000 +0200

 @@ -22205,7 +22205,7 @@

  	tls_first_minor=14

  	tls_as_opt="-m64 -Aesame --fatal-warnings"

  	;;

 -  sh-*-* | sh[34]-*-*)

 +  sh-*-* | sh[34]*-*-*)

      conftest_s='

  	.section ".tdata","awT",@progbits

  foo:	.long	25

 diff -durN gcc-4.4.0.orig/gcc/configure.ac gcc-4.4.0/gcc/configure.ac

 --- gcc-4.4.0.orig/gcc/configure.ac	2009-05-27 21:38:08.000000000 +0200

 +++ gcc-4.4.0/gcc/configure.ac	2009-05-27 21:38:42.000000000 +0200

 @@ -2673,7 +2673,7 @@

  	tls_first_minor=14

  	tls_as_opt="-m64 -Aesame --fatal-warnings"

  	;;

 -  sh-*-* | sh[34]-*-*)

 +  sh-*-* | sh[34]*-*-*)

      conftest_s='

  	.section ".tdata","awT",@progbits

  foo:	.long	25