pg_statistic MCVs use float4 but extended stats use float8

It seems odd that stats_ext uses double:

postgres=# SELECT attrelid::regclass, attname, atttypid::regtype, relkind FROM pg_attribute a JOIN pg_class c ON
c.oid=a.attrelidWHERE attname='most_common_freqs';
 
      attrelid      |      attname      |      atttypid      | relkind 
--------------------+-------------------+--------------------+---------
 pg_stats           | most_common_freqs | real[]             | v
 pg_stats_ext       | most_common_freqs | double precision[] | v
 pg_stats_ext_exprs | most_common_freqs | real[]             | v

I'm not sure if that's deliberate ?

This patch changes extended stats to match.

-- 
Justin