Added test for rust-lang#357 (rust-lang#709)

Author: zhassan-aws

src/test/rmc/SubSlice/subslice2_fixme.rs

@@ -27,8 +27,8 @@
 //           * #c_type: unsigned_long_int
 //       * value: 1
 //
-// Full support for subslice projection to be added in
-// https://github.com/model-checking/rmc/issues/357
+// This issue is captured in:
+// https://github.com/model-checking/rmc/issues/708
 
 fn main() {
     let arr = [1, 2, 3];

src/test/rmc/SubSlice/subslice3.rs

@@ -0,0 +1,12 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+fn main() {
+    let slice = &[1, 2, 3][..];
+    if let [head, tail @ ..] = slice {
+        assert!(head == &slice[0]);
+        assert!(tail == &slice[1..]);
+    } else {
+        unreachable!();
+    }
+}