Add a sleep command between cargo publish invocations.

Crates.io no longer synchronously updates the crate index, so sleep for
a few seconds between cargo publish invocations to give it time to
update.

cranelift/publish-all.sh

@@ -44,4 +44,8 @@ for crate in \
     faerie umbrella simplejit
 do
     echo cargo publish --manifest-path "cranelift-$crate/Cargo.toml"
+
+    # Sleep for a few seconds to allow the server to update the index.
+    # https://internals.rust-lang.org/t/changes-to-how-crates-io-handles-index-updates/9608
+    echo sleep 3
 done