Semantics of adding non-number objects to numbers

[smarr]

A SOM spec should define what needs to happen on operations like: 0 + 'a'.

Most SOMs currently error with some implementation-level exception/crash.

CSOM goes a little wild:

---> 0 + 'a'
it = 4411137528
---> 0 + 'a'
it = 4411139328

Perhaps this needs to trigger Integer>>#unsupportedArgument:, or a NotANumber error.

A spec definitely needs to have an opinion on such programs.

See softdevteam/yksom@4fb753c and softdevteam/yksom#37.