Function minimize_single_call_counterexample 

pub(crate) fn minimize_single_call_counterexample(
    function: &Function,
    call: &SymbolicCounterexampleCall,
    max_attempts: usize,
    still_fails: impl FnMut(&SymbolicCounterexampleCall) -> bool,
) -> Option<MinimizedSingleCall>

Minimizes a stateless symbolic counterexample with ABI-valid candidates only.

still_fails must concretely replay the candidate and return true only when it preserves the already-confirmed failure.