Vendor dependencies

Let's see how I like this workflow.

vendor/cxx/tools/buck/prelude/apple/apple_package.bzl

@@ -0,0 +1,23 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under both the MIT license found in the
+# LICENSE-MIT file in the root directory of this source tree and the Apache
+# License, Version 2.0 found in the LICENSE-APACHE file in the root directory
+# of this source tree.
+
+def apple_package_impl(ctx: "context") -> ["provider"]:
+    bundle = ctx.attrs.bundle
+    ipa_name = "{}.ipa".format(bundle.label.name)
+    app = bundle[DefaultInfo].default_outputs[0]
+
+    payload = ctx.actions.copy_file("Payload", app)
+
+    package = ctx.actions.declare_output(ipa_name)
+
+    # TODO(T96496412): Add support for compression levels and SwiftSupport
+    # TODO(T110378117): Pull this into a shared zip utility function
+
+    zip = cmd_args(["(cd \"", cmd_args(payload).parent(), "\" && zip -X -r - \"", payload.basename, "\") > ", package.as_output()], delimiter = "")
+    ctx.actions.run(["sh", "-c", zip], category = "apple_package_zip")
+
+    return [DefaultInfo(default_outputs = [package])]