Revert "Use RPython overflow check for arithmetics"
Revert "Use RPython overflow check for arithmetics"

This reverts commit d9174b65259e0d62b951c65c4d73de2cb4e36cd2.

Doesn't work naively as used here, because the SOM integer range is not preserved.
Not sure whether I would want it in the first place, but well, it is the way it is at the moment...

Signed-off-by: Stefan Marr <46f1a0bd5592a2f9244ca321b129902a06b53e03@stefan-marr.de>

smarr/PySOM,SOM-st/RTruffleSOM,SOM-st/PySOM,SOM-st/RTruffleSOM,smarr/RTruffleSOM,SOM-st/RPySOM,SOM-st/RPySOM,smarr/PySOM,smarr/RTruffleSOM,SOM-st/PySOM