Clarify handling of special-case values in bootstrap catalog data.
I (tgl) originally coded the special case for pg_proc.pronargs as
though it were a kind of default value. It seems better though to
treat computable columns as an independent concern: this makes the
code clearer, and probably a bit faster too since we needn't do
work inside the per-column loop.
Improve related comments, as well, in the expectation that there
might be more cases like this in future.
John Naylor, some additional comment-hacking by me
projects / postgresql / commit