libc/eglibc: does no longer support LinuxThreads

LinuxThreads are dead. Buried 6 feet under. Long forgotten.
Time for mourning has to come to an end.

But fear not, younster, for we have a great successor as NPTL!
Times for rejoicing have come, now!

LinuxThreads are dead. Long live NPTL!

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

 # Compute s390-specific values

 CT_DoArchTupleValues() {

     # That's the only thing to override

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

         CT_TARGET_ARCH="s390x${CT_ARCH_SUFFIX}"

     fi

 }