[Bug libgcc/81199] fallback definition of count_leading_zeros references hidden symbol

[coypu at sdf dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81199

--- Comment #1 from coypu <coypu at sdf dot org> ---
Maybe expose __clz_tab but only in the fallback definition case, and not make
it hidden.