Add zero, NaN, Inf and -Inf tests for arc methods
Add zero, NaN, Inf and -Inf tests for arc methods

They go in the `turtle::tests::ignores_nan_inf_zero` function and check
that all the possible combinations of those do not make the turtle move.

Signed-off-by: Paul Mabileau <a3aedf8c87c1af3dfeae5f57ddf6d5ae82ad981f@hotmail.fr>

sunjay/turtle,sunjay/turtle,sunjay/turtle