Tests the emitted warning on use of deprecated aliases.

This is required to automatically unroll loops with conditions such as
`nondet && x < 100`, as this is converted by the Frama-C kernel as two
nested conditional statements, where only the second one can be used to
unroll the loop.

If the variable used in the exit condition of the loop is not incremented within
the loop, but is assigned to the value of another lvalue, the heuristic uses
this second lvalue instead.
This is especially useful to deal with some temporary variables introduced
by Frama-C to translate condition such as (i++ < l).