I went through the senders of #instVarAt: in the base image, and found 
that this feature is never used. Sends are guarded by #instSize, or the 
receiver is self or a well-known pointers object.

Levente

On Wed, 29 Mar 2017, Eliot Miranda wrote:

> Hi All,
>     another dubious piece of code is this:
> 
> SmallInteger>>instVarAt: i  "Small integer has to be specially handled."
> 
> i = 1 ifTrue: [^self].
> self error: 'argument too big for small integer instVarAt:'
> 
> Either this is important and should be replicated in Character and SmallFloat64 (the other two immediate classes) or it should be discarded.  It's
> ancient (pre version stamps).  I vote to nuke it.  Opinions?
> _,,,^..^,,,_
> best, Eliot
> 
>