pgsql: Fix log_statement to properly recognize SELECT INTO and CREATE

Log Message:
-----------
Fix log_statement to properly recognize SELECT INTO and CREATE TABLE AS
and DDL statements.

Backpatch fix to 8.0.X.

Per report from Murthy Kambhampaty

Modified Files:
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pgsql/src/backend/tcop:
postgres.c (r1.444 -> r1.445)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/postgres.c.diff?r1=1.444&r2=1.445)