Add compile-tests to zerocopy

This commit just adds the framework necessary to run these tests, but
does not add any compile-tests. Tests will need to be added to complete
 #17.

tests/compiletest.rs

@@ -0,0 +1,25 @@
+// Copyright 2022 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use std::path::PathBuf;
+
+use compiletest_rs::{common::Mode, Config};
+
+#[test]
+fn ui() {
+    let mut config = Config {
+        // Uncomment to bless tests.
+        // bless: true,
+        mode: Mode::Ui,
+        src_base: PathBuf::from("tests/ui"),
+        target_rustcflags: Some("-L target/debug -L target/debug/deps".to_string()),
+        build_base: PathBuf::from("target/ui"),
+        ..Default::default()
+    };
+
+    config.link_deps();
+    config.clean_rmeta();
+
+    compiletest_rs::run_tests(&config);
+}