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 -ur uClibc-0.9.29/libc/inet/resolv.c uClibc-0.9.29-patched/libc/inet/resolv.c

 --- uClibc-0.9.29/libc/inet/resolv.c	2007-04-23 12:01:05.000000000 -0500

 +++ uClibc-0.9.29-patched/libc/inet/resolv.c	2007-05-09 18:05:33.563404419 -0500

 @@ -1700,7 +1700,7 @@

  int gethostent_r(struct hostent *result_buf, char *buf, size_t buflen,

  	struct hostent **result, int *h_errnop)

  {

 -    int ret;

 +    int ret = HOST_NOT_FOUND;

      __UCLIBC_MUTEX_LOCK(mylock);

      if (__gethostent_fp == NULL) {