Ensure array is always copied during destructure

packages/babel-plugin-transform-es2015-destructuring/test/fixtures/destructuring/issue-5090/exec.js

@@ -0,0 +1,9 @@
+const assign = ([...arr], index, value) => {
+  arr[index] = value;
+  return arr;
+}
+
+const arr = [1, 2, 3];
+assign(arr, 1, 42);
+
+assert.deepEqual(arr, [1, 2, 3]);