Fix `fused_pointer_except_null` test undefined behavior
Fix `fused_pointer_except_null` test undefined behavior

Signed-off-by: Stefan Behnel <11627668ff138054b9ab08f183b1e3f7c3ef77a0@behnel.de>

cython/cython,da-woods/cython,scoder/cython,da-woods/cython,scoder/cython,scoder/cython,da-woods/cython,cython/cython,cython/cython,scoder/cython,cython/cython,da-woods/cython