export isl_multi_*_involves_nan
export isl_multi_*_involves_nan

These complement the already exported isl_val_is_nan.

Signed-off-by: Sven Verdoolaege <dd860110a62b19214c4ee03aec0abffecb4e86b8@cerebras.net>

Meinersbur/isl,Meinersbur/isl,Meinersbur/isl,Meinersbur/isl