fails:BigDecimal.induced_from returns the passed argument when passed a BigDecimal
fails:BigDecimal.induced_from converts passed Fixnums to BigDecimal
fails:BigDecimal.induced_from converts passed Bignums to BigDecimal
fails:BigDecimal.induced_from does not try to convert non-Integers to Integer using #to_i
fails:BigDecimal.induced_from raises a TypeError when passed a non-Integer
