Bugfix: Performance is slow due to process signal checks (more).

Bugfix: Performance is slow due to process signal checks (more).

This is a follow up to the previous commit similarly named.
I forgot to hit the save button for the changes to FSS Basic List files in my editor.

The cost of the system call for checking if a signal is received is more expensive than I have previously imagined.
I also was not sure where I should handle the signals and I arbitrarily put them inside loops.

Reduce the number of checks.
Reduce the number of the system call to check the process signal using modulus math.

The performance difference is most notable when using the byte_dump program.

This focuses on solving the immediate performance bug.
I still have not done any extensive performance investigations and I expect this to still have significant room for improvement.