Added specializations for #doIndex: and #do:
Added specializations for #doIndex: and #do:

TruffleSOM has them, so, let's see wether they are useful here, too.

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

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