dev-rust/hermit-abi: Add stub ebuild.

This is ABI bindings for the hermit unikernel that will be
conditionally used when compiling library crates for that target.
We'll never need it.

BUG=b:171728575
TEST=emerge-trogdor deqp-runner

Change-Id: I2d324e3bfa1eb7009af093fea33a16a5946f539c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2521897
Tested-by: Eric Anholt <anholt@google.com>
Reviewed-by: Eric Anholt <anholt@google.com>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Commit-Queue: Eric Anholt <anholt@google.com>
diff --git a/dev-rust/hermit-abi/hermit-abi-0.1.3.ebuild b/dev-rust/hermit-abi/hermit-abi-0.1.3.ebuild
new file mode 100644
index 0000000..760e39c
--- /dev/null
+++ b/dev-rust/hermit-abi/hermit-abi-0.1.3.ebuild
@@ -0,0 +1,15 @@
+# Copyright 2020 The Chromium OS Authors. All rights reserved.
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI="7"
+
+CROS_RUST_EMPTY_CRATE=1
+
+inherit cros-rust
+
+DESCRIPTION="Empty ${PN} crate"
+HOMEPAGE="https://github.com/hermitcore/libhermit-rs"
+
+LICENSE="|| ( MIT Apache-2.0 )"
+SLOT="${PV}/${PR}"
+KEYWORDS="*"