Remove CloneShim-related logic for TyKind::Array

As of rust-lang/rust#86041, `Clone` impls for array
types are now implemented in library code rather than using `clone` shims. As
such, the `TyKind::Array` case in the code surrounding `CloneShim`s is now
unreachable. This removes the code to simplify things.

To prevent future regressions, this adds a test case that `clone`s an array and
ensures that it does not emit a `don't know how to build clone shim` warning.

Fixes #197.

Author: RyanGlScott

src/analyz/ty_json.rs

@@ -389,7 +389,6 @@ impl<'tcx> ToJson<'tcx> for ty::Instance<'tcx> {
             }),
             ty::InstanceKind::CloneShim(did, ty) => {
                 let sub_tys = match *ty.kind() {
-                    ty::TyKind::Array(t, _) => vec![t],
                     ty::TyKind::Tuple(ts) => ts[..].to_owned(),
                     ty::TyKind::Closure(_closure_did, args) =>
                         args.as_closure().upvar_tys()[..].to_owned(),

tests/common.sh

@@ -33,3 +33,18 @@ expect_json_contains() {
     exit 1
   fi
 }
+
+expect_output_does_not_contain() {
+  set +e
+  output=$("${@:2}" 2>&1)
+  status=$?
+  set -e
+
+  if echo "$output" | grep -q "$1"; then
+    echo "Output contains '$1'"
+    echo "$output"
+    return 1
+  fi
+
+  echo "Output does not contain '$1'"
+}

tests/issues/test0197/README.md

@@ -0,0 +1,8 @@
+A test which ensures that `mir-json` can successfully compile a test case that
+`clone`s an array without warnings, the subject of
+[mir-json#197](https://github.com/GaloisInc/mir-json/issues/197). This used to
+require creating a `clone` shim, but as of
+https://github.com/rust-lang/rust/pull/86041, `Clone` impls for array types are
+now implemented in library code rather using `clone` shims. As such, `mir-json`
+no longer needs any `clone` shim logic for arrays, and it should be able to
+compile the given test case without issues.

tests/issues/test0197/test.rs

@@ -0,0 +1,5 @@
+pub fn f() {
+    let x = [1, 2, 3];
+    let y = x.clone();
+    assert!(x == y);
+}

tests/issues/test0197/test.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+set -euo pipefail
+source "$(dirname "$0")/../../common.sh"
+
+expect_output_does_not_contain "don't know how to build clone shim" \
+  saw-rustc test.rs \
+    --target "$(rustc --print host-tuple)"