Support serialisation of pgtype.Type

[nicois]

I am using pgx(pool) with a database where there are a lot of custom types which need registering. Even using some smarts to only register the types actually used by a given application, it still takes multiple seconds to collect all the *pgtype.Type values.
While this is acceptable for non-interactive long-running applications, this reduces the viability of using pgx to build command-line tools.
I have tried to mitigate this problem by caching the results of LoadType, but I see:

some values are not fixed-sized in type pgtype.Type

Would it be possible to, one way or another, allow Type to be serialised?

[jackc]

Would it be possible to, one way or another, allow Type to be serialised?

Yes, but it seems rather error prone. I'm more inclined to improve performance of loading types like you recommended in jackc/pgx#2030. Also, only bug fixes to this older version.