LIST() and HASH() don't have the rigth SIZE(/n_dim)

[alaingdl]

Thanks to some super simple tests in error in test_isa.pro, I got :

GDL> size(hash(),/n_di)
           1
GDL> size(list(),/n_di)
           1

[...]
IDL> size(hash(),/n_di)
           0
IDL> size(list(),/n_di)
           0