rust: workaround snapshot having target-word-size
rust: workaround snapshot having target-word-size

jmesmon/meta-rust,jmesmon/meta-rust,meta-rust/meta-rust,cardoe/meta-rust,cardoe/meta-rust,jmesmon/meta-rust,starlab-io/meta-rust,meta-rust/meta-rust,jmesmon/meta-rust,meta-rust/meta-rust,meta-rust/meta-rust,starlab-io/meta-rust,cardoe/meta-rust,meta-rust/meta-rust,cardoe/meta-rust