Fix encoding of link_section and no_mangle cross crate
Fixes https://github.com/rust-lang/rust/issues/144004
``@bjorn3`` suggested using the `codegen_fn_attrs` query but given that these attributes are not that common it's probably fine to just always encode them. I can also go for that solution if it is preferred but that would require more changes.
r? ``@jdonszelmann`` ``@fmease`` (whoever feels like it)