The `std::mem::offset_of` macro was introduced in Rust 1.77.0.
In the passing, mark the function as `const`, as suggested in the
comment. Not sure which compiler version that requires, but it works
with what have currently.
Re-export only things that are used by other modules.
In the future, I'm imagining that we run bindgen twice, for Postgres
v14 and v15. The two sets of bindings would go into separate
'bindings_v14' and 'bindings_v15' modules.
Rearrange postgres_ffi modules.
Move function, to avoid Postgres version dependency in timelines.rs
Move function to generate a logical-message WAL record to postgres_ffi.
