libc/glibc: do not consume parameters when parsing them

Currently, there are two constructs used to parse arguments in
glibc backends, one that consumes args as they are parsed, and
one that does not.

Always use the construct that does not eat args as they are parsed.

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

}