Just in the off-chance this is useful to someone: If you find yourself needing the Postgres parser elsewhere, e.g. in some custom tooling to analyze SQL queries, I extracted it into a library some time ago:

https://github.com/lfittl/libpg_query

Your comment still applies though, as a lot of the parser output is very specific to the chosen Postgres version (10 at the moment) and can change unpredictably.