CREATE TABLE foo (x,y,z) AS SELECT ... can't apply target column names

to the target list in gram.y; it must wait till after expansion of the
target list in analyze.c.  Per bug report 4-Nov:
lx=# CREATE TABLE abc (a char, b char, c char);
CREATE
lx=# CREATE TABLE xyz (x, y, z) AS SELECT * FROM abc;
ERROR:  CREATE TABLE/AS SELECT has mismatched column count