debug/gdb: update the version strings

Almost all versions have been renamed, but the gdb folks did not
setup legacy symlinks.

For more information, see this message:
http://sourceware.org/ml/gdb/2011-09/msg00002.html

Reported-by: ManuelStahl <manuel.stahl@iis.fraunhofer.de>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 # Compute sparc-specific values

 CT_DoArchTupleValues() {

     # That's the only thing to override

     if [ "${CT_ARCH_64}" = "y" ]; then

         CT_TARGET_ARCH="${CT_ARCH}64"

     fi

 }