Unwinding assertion failures do not clearly indicate which loop is involved

[tedinski]

Check 67: .unwind.0
         - Status: FAILURE
         - Description: "unwinding assertion loop 0"


SUMMARY: 
 ** 1 of 67 failed (66 undetermined)
Failed Checks: unwinding assertion loop 0

What function? What loop?

I vaguely recall we used to see that information, so something changed.

Raw cbmc output:

** Results:
[.unwind.0] unwinding assertion loop 0: FAILURE

[tedinski]

Probably a bug on our side, I did a quick test with cbmc:

** Results:
test.c function main
[main.unwind.0] line 3 unwinding assertion loop 0: FAILURE