Remove BigInteger from tests

- was forgotten in the relevant commit

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Fixed incorrect assertion in left shift primitive

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added specialization for SSymbol and long in #= primitive

Signed-off-by: Stefan Marr <git@stefan-marr.de>