Remove overflow checks for integer constants

[sim642]

As found by @Robotechnic, we perform an overflow check for each integer literal in the program in IntDomTuple.of_int and friends.
When this check is removed (commented out here), nothing seems to break:

• All tests pass.
• No unsoundness is revealed on sv-benchmarks (with 60s timeout).

This brings into question whether this check has any purpose at all. I haven't dug into its git history, but it's something we should consider at some point.

[sim642]

This happens inside of_const in the constant evaluation in base:

analyzer/src/analyses/base.ml

Lines 808 to 810 in 92007d5

	| Const (CInt (num,ikind,str)) ->
	(match str with Some x -> if M.tracing then M.tracel "casto" "CInt (%s, %a, %s)" (Z.to_string num) d_ikind ikind x | None -> ());
	Int (ID.cast_to ikind (IntDomain.of_const (num,ikind,str)))

Notably, it's immediately followed by a cast to the created ik, so we actually do two overflow checks per integer literal.
Even if it is necessary for something I'm not yet aware of, there's definitely no reason to do it twice.

[sim642]

CIL seems to ensure that integer constants fit their type, so neither of the overflow checks should be necessary.
Worse yet, it silently truncates some constants, so Goblint even doesn't get a chance to check their overflow: goblint/cil#194.
There, in the volatile int case, there's an explicit CastE and we report the overflow on the actual cast, not on the integer literal (which is inferred to be a ILong by some rules).