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>

Enable using a shell other than bash.

Courtesy "Martin Guy" <martinwguy@yahoo.it>

http://sourceware.org/ml/crossgcc/2008-08/msg00037.html

--- binutils-2.18.orig/ld/genscripts.sh	2007-08-12 20:00:07.000000000 +0100

+++ binutils-2.18/ld/genscripts.sh	2008-08-25 16:09:54.000000000 +0100

@@ -398,9 +398,11 @@

     . $em_script

     em_script=$current_script

   }

-  fragment()

+  

+  alias fragment='em_lineno=$LINENO; fragment_em'

+  fragment_em()

   {

-    local lineno=$[${BASH_LINENO[0]} + 1]

+    local lineno=$[$em_lineno + 1]

     echo >> e${EMULATION_NAME}.c "#line $lineno \"$em_script\""

     cat >> e${EMULATION_NAME}.c

   }