pgsql: Prevent certain symbols that are used for both typedefs and

Log Message:
-----------
Prevent certain symbols that are used for both typedefs and variable
names from being added to pgindent's typedef list.  The existance of
them caused weird formatting in the date/type files, and in keywords.c.

Backpatch to 8.1.X.

Modified Files:
--------------
    pgsql/src/tools:
        find_typedef (r1.4 -> r1.5)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/find_typedef.diff?r1=1.4&r2=1.5)
    pgsql/src/tools/pgindent:
        pgindent (r1.84 -> r1.85)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/pgindent/pgindent.diff?r1=1.84&r2=1.85)