Can someone with some background knowledget on the opal compiler,
look at my fix for issue 12442.

It seems to work, but I don't like it.

There were 2 problems with OCUnusedVariableWarning, removing unused temps:
1. Removes the RBTemporaryNode and updates the source text but does
not correct the sourcetext offset of the remaining nodes.
2. Removed temporaries are left in the methodnode/blocknode scope

One additional issue, if you have removed all temporaries, the two bars
from the empty variable declaration still there


nicolai