cc/gcc: do not force use of non-vital companion libraries

While GMP and MPFR are required by gcc>=4.3 (to build the frontends),
and MPC is required by gcc>=4.5, the other libs are not. If they are
present then gcc will enable advanced features; if they are missing,
then gcc will (should) simply disable those features.

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

 #!/bin/sh

 SKIP_ME="### CT_NG SKIP ME ###"

 skip_me=$(($(cat "${0}" |@@grep@@ --binary-files=text -o -b -E "^${SKIP_ME}$" |cut -d : -f 1)+${#SKIP_ME}+1))

 dd if="${0}" bs=${skip_me} skip=1 2>/dev/null |bzcat

 exit 0

 ### CT_NG SKIP ME ###