generating function default settings from pg_proc.dat

Motivated by Bug 19409 [1] I decided to do something about a wart that 
has bugged me for a while, namely the requirement to write stuff in 
system_views.sql if you need to specify default values for function 
arguments. Here's my attempt. The first patch here sets up the required 
infrastructure. genbki.pl creates a file called function_defaults.sql 
which is run by initdb at the appropriate time. There are two new fields 
in pg_proc.dat entries: proargdflts,and provariadicdflt. These are 
parsed and the appropriate CREATE OR REPLACE statement is generated and 
placed in function_defaults.sql. The second patch applies this treatment 
to 37 function definitions and removes the corresponding statements from 
system_views.sql. This gets us closer to having pg_proc.dat as a single 
source of truth.


cheers


andrew


[1] 
https://www.postgresql.org/message-id/19409-e16cd2605e59a4af%40postgresql.org

--
Andrew Dunstan
EDB: https://www.enterprisedb.com