The following completion patterns are added:
- CREATE TABLE <name> with '(', OF or PARTITION OF.
- CREATE TABLE <name> OF with list of composite types.
- CREATE TABLE name (...) with PARTITION OF, WITH, TABLESPACE, ON
COMMIT (depending on the presence of a temporary table).
- CREATE TABLE ON COMMIT with actions (only for temporary tables).

Author: Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/d8j1s77kdbb.fsf@dalvik.ping.uio.no