Add a test for breakpoint (rust-lang#1022)

* Add a test for `breakpoint`

* Convert into an `expected` test

* Update comment on test

Author: adpaco-aws

tests/expected/intrinsics/breakpoint/expected

@@ -0,0 +1,2 @@
+SUCCESS\
+assertion failed: true

tests/expected/intrinsics/breakpoint/main.rs

@@ -0,0 +1,12 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+// Check that `breakpoint` is supported (generates a `SKIP` statement)
+// and that the assertion after `breakpoint` continues to be reachable
+#![feature(core_intrinsics)]
+
+#[kani::proof]
+fn main() {
+    unsafe { std::intrinsics::breakpoint() };
+    assert!(true);
+}