pgsql: Add transformed flag to nodes/*funcs.c for CREATE STATISTICS

Add transformed flag to nodes/*funcs.c for CREATE STATISTICS

Commit a4d75c86bf added a new flag, tracking if the statement was
processed by transformStatsStmt(), but failed to add this flag to
nodes/*funcs.c.

Catversion bump, due to adding a flag to copy/equal/out functions.

Reported-by: Noah Misch
Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d57ecebd128cdf2f4844a2ea4d35ff28d7d69be8

Modified Files
--------------
src/backend/nodes/copyfuncs.c    | 1 +
src/backend/nodes/equalfuncs.c   | 1 +
src/backend/nodes/outfuncs.c     | 1 +
src/include/catalog/catversion.h | 2 +-
4 files changed, 4 insertions(+), 1 deletion(-)