[CIL users] constFold soundness

[Nathan C. <co...@cs...>]

Upon using some randomly generated C to test my CIL extensions, I 
believe there might be an unsoundness in the constant folder. 

My understanding of shifts is that both the left shift and the right 
shift are undefined if their right operand is greater than the bit width 
of the left operand. 

Also, I believe that even though shifting a negative number right is 
normally sign extended, the official behavior is not defined (could have 
0s or 1s pushed on). 

I am still using CIL 1.3.2, but this does not appear to have been 
addressed in 1.3.3 according to the change log.

I have two questions: First, am I correct in my understanding of these 
shift corner cases?  Second, if this is a problem, do I need to write 
the fix myself or do you have it somewhere? 

Nathan