crux-mir: add tests for load/store and drop of zsts

Author: spernsteiner

crux-mir/test/conc_eval/drop/zst.rs

@@ -0,0 +1,27 @@
+//! Test drop for zero-sized types.
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+static DROPPED: AtomicUsize = AtomicUsize::new(0);
+
+struct S;
+impl Drop for S {
+    fn drop(&mut self) {
+        DROPPED.fetch_add(1, Ordering::Relaxed);
+    }
+}
+
+fn f<T>(x: T) {}
+
+#[cfg_attr(crux, crux::test)]
+fn crux_test() -> usize {
+    {
+        let s = S;
+        let s2 = (S,);
+        f(s2);
+    }
+    DROPPED.load(Ordering::Relaxed)
+}
+
+pub fn main() {
+    println!("{:?}", crux_test());
+}

crux-mir/test/conc_eval/tuple/load_store_zst.rs

@@ -0,0 +1,17 @@
+fn my_replace<T: Clone>(r: &mut T, x: T) -> T {
+    let old = (*r).clone();
+    *r = x;
+    old
+}
+
+#[cfg_attr(crux, crux::test)]
+fn crux_test() {
+    let mut x = ();
+    my_replace(&mut x, ());
+    let mut y = (1, ());
+    my_replace(&mut y.1, ());
+}
+
+pub fn main() {
+    println!("{:?}", crux_test());
+}