Use checked_sub instead of saturating_sub

Author: tiif

src/shims/time.rs

@@ -176,7 +176,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 ("tm_hour", dt.hour().into()),
                 ("tm_mday", dt.day().into()),
                 ("tm_mon", dt.month0().into()),
-                ("tm_year", dt.year().saturating_sub(1900).into()),
+                ("tm_year", dt.year().checked_sub(1900).unwrap().into()),
                 ("tm_wday", dt.weekday().num_days_from_sunday().into()),
                 ("tm_yday", dt.ordinal0().into()),
                 ("tm_isdst", tm_isdst),