Log Message:
-----------
Add some comments about why function parameter default expressions are
restricted.
Modified Files:
--------------
pgsql/src/backend/commands:
functioncmds.c (r1.106 -> r1.107)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/functioncmds.c?r1=1.106&r2=1.107)