Changed created functions to persist on the root

[Hydrocharged]

This changes created functions such that they're now written to the root value, instead of being added to the global function list. This also supports overloading created functions.

[github-actions]

	Main	PR
covering_index_scan_postgres	359.79/s	364.89/s	+1.4%
index_join_postgres	155.05/s	154.35/s	-0.5%
index_join_scan_postgres	183.71/s	185.16/s	+0.7%
index_scan_postgres	12.59/s	12.56/s	-0.3%
oltp_point_select	2855.77/s	2784.14/s	-2.6%
oltp_read_only	1909.45/s	1885.37/s	-1.3%
select_random_points	113.28/s	113.09/s	-0.2%
select_random_ranges	127.04/s	130.20/s	+2.4%
table_scan_postgres	11.19/s	11.12/s	-0.7%
types_table_scan_postgres	5.65/s	5.61/s	-0.8%

[github-actions]

	Main	PR
Total	42090	42090
Successful	15651	15654
Failures	26439	26436
Partial Successes1	5211	5212

	Main	PR
Successful	37.1846%	37.1917%
Failures	62.8154%	62.8083%

${\color{red}Regressions (3)}$

plpgsql

QUERY:          create function f1(in i int, out j int) as $$
begin
  j := i+1;
  return;
end$$ language plpgsql;
RECEIVED ERROR: function "f1" already exists with same argument types (errno 1105) (sqlstate HY000)

QUERY:          create function void_return_expr() returns void as $$
begin
    perform 2+2;
end;$$ language plpgsql;
RECEIVED ERROR: function "void_return_expr" already exists with same argument types (errno 1105) (sqlstate HY000)

QUERY:          create function missing_return_expr() returns int as $$
begin
    perform 2+2;
end;$$ language plpgsql;
RECEIVED ERROR: function "missing_return_expr" already exists with same argument types (errno 1105) (sqlstate HY000)

${\color{lightgreen}Progressions (6)}$

domain

QUERY: select doubledecrement(null);

indexing

QUERY: select indexrelid::regclass, indrelid::regclass
  from pg_index where indexrelid::regclass::text like 'idxpart%';

regproc

QUERY: SELECT to_regclass('pg_catalog.pg_class');

sequence

QUERY: SELECT nextval('sequence_test'::regclass);

QUERY: SELECT nextval('sequence_test'::regclass);

QUERY: SELECT nextval('sequence_test'::regclass);

Footnotes

1. These are tests that we're marking as Successful, however they do not match the expected output in some way. This is due to small differences, such as different wording on the error messages, or the column names being incorrect while the data itself is correct. ↩

[fulghum]

Looks great! Awesome work!