BUG #5942: pg_trgm.sql has cyclic dependency on type gtrgm creation

The following bug has been logged online:

Bug reference: 5942
Logged by: Arthur Nascimento
Email address: tureba@gmail.com
PostgreSQL version: 9.0.3
Operating system: Linux
Description: pg_trgm.sql has cyclic dependency on type gtrgm creation
Details:

When creating the gtrgm type, it depends on gtrgm_{in,out}. These functions
also depend on the type, so there is a cyclic dependency on creation of the
type.

The command psql -f sharedir/contrib/pg_trgm.sql crashes for me accusing
this error.

According to the CREATE TYPE documentation, this can be solved by adding a
"CREATE TYPE gtrgm;" line before the functions are defined. This solution
worked locally for me by including that command between lines 40 and 41 of
the file.

A snippet of the offending code of contrib/pg_trgm.sql, lines 40 to 55:
-- gist key
CREATE OR REPLACE FUNCTION gtrgm_in(cstring)
RETURNS gtrgm
AS '$libdir/pg_trgm'
LANGUAGE C STRICT;

CREATE OR REPLACE FUNCTION gtrgm_out(gtrgm)
RETURNS cstring
AS '$libdir/pg_trgm'
LANGUAGE C STRICT;

CREATE TYPE gtrgm (
INTERNALLENGTH = -1,
INPUT = gtrgm_in,
OUTPUT = gtrgm_out
);