debug/gdb: we don't care if the host tic is shared or static

Because we need our own host tic, we have to build it; and we do build
it statically for now.

But as MacOS/Darwin/Whatever-you-call-it does not support static linking
(what a shame!), it fails.

Anyway, we don't really care it being shared, in the end.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from 41bd6777fa4f767d6264db7c58986920014fd708)

# Options specific to crosstool-NG acting as a backend

config IS_A_BACKEND

    string

    option env="CT_IS_A_BACKEND"

config BACKEND

    bool

    default y if IS_A_BACKEND = "y" || IS_A_BACKEND = "Y"

config BACKEND_ARCH

    string

    option env="CT_BACKEND_ARCH"

config BACKEND_KERNEL

    string

    option env="CT_BACKEND_KERNEL"

config BACKEND_LIBC

    string

    option env="CT_BACKEND_LIBC"