feature f1 {
    sub A from [A.alt1 A.alt2];
    sub B from [B.alt1 B.alt2 B.alt3];
    sub C from [C.alt1];
} f1;


# Exact same content as feature f1; lookup should be shared.
feature f2 {
    sub A from [A.alt1 A.alt2];
    sub B from [B.alt1 B.alt2 B.alt3];
    sub C from [C.alt1];
} f2;