Add tests for fixed issues. (model-checking#3484)

model-checking#2239 and model-checking#3022 are resolved in Kani v0.5.4. Add tests for them.

Resolves model-checking#2239

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 and MIT licenses.

tests/expected/issue-2239/issue_2239.expected

@@ -0,0 +1,5 @@
+test_trivial_bounds.unreachable.1\
+- Status: FAILURE\
+- Description: "unreachable code"
+
+VERIFICATION:- FAILED

tests/expected/issue-2239/issue_2239.rs

@@ -0,0 +1,15 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+#![feature(trivial_bounds)]
+#![allow(unused, trivial_bounds)]
+
+#[kani::proof]
+fn test_trivial_bounds()
+where
+    i32: Iterator,
+{
+    for _ in 2i32 {}
+}
+
+fn main() {}

tests/expected/issue-3022/issue_3022.expected

@@ -0,0 +1,5 @@
+main.assertion\
+- Status: SUCCESS\
+- Description: "assertion failed: inner == func2.inner"
+
+VERIFICATION:- SUCCESSFUL

tests/expected/issue-3022/issue_3022.rs

@@ -0,0 +1,24 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+type BuiltIn = for<'a> fn(&str);
+
+struct Function {
+    inner: BuiltIn,
+}
+
+impl Function {
+    fn new(subr: BuiltIn) -> Self {
+        Self { inner: subr }
+    }
+}
+
+fn dummy(_: &str) {}
+
+#[kani::proof]
+fn main() {
+    let func1 = Function::new(dummy);
+    let func2 = Function::new(dummy);
+    let inner: fn(&'static _) -> _ = func1.inner;
+    assert!(inner == func2.inner);
+}