tools/nolibc: add __nolibc_static_assert()

tools/nolibc: add __nolibc_static_assert()

Add a wrapper for _Static_assert() to use within nolibc.
While _Static_assert() itself was only standardized in C11,
in GCC and clang dialects it is also available in older standards.

Link: https://lore.kernel.org/lkml/20251203192330.GA12995@1wt.eu/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20251220-nolibc-uapi-types-v3-13-c662992f75d7@weissschuh.net