Make `ability_sets` test deterministic cross platform.
Make `ability_sets` test deterministic cross platform.

Replace the use of the `jrand48()` random number generator in the
`ability_sets_alloc_method_4_random_test()` function with the linear
congruent generator behind the `rnd_alloc_lcg()` function.

donmccaughey/FiendsAndFortune,donmccaughey/FiendsAndFortune,donmccaughey/FiendsAndFortune