pgsql: Doc: move some catalogs.sgml entries to the right place.

Doc: move some catalogs.sgml entries to the right place.

pg_statistic_ext_data.stxdexpr was listed under the wrong catalog,
as was pg_stats_ext.exprs.  Also there was a bogus entry for
pg_statistic_ext_data.stxexprs.  Apparently a merge failure in
commit a4d75c86b.

Guillaume Lelarge and Tom Lane

Discussion: https://postgr.es/m/CAECtzeUHw+w64eUFVeV_2FJviAw6oZ0wNLkmU843ZH4hAQfiWg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/713a431c781fbfe1a22fae4991836077f0f4c513

Modified Files
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doc/src/sgml/catalogs.sgml | 37 ++++++++++++++-----------------------
1 file changed, 14 insertions(+), 23 deletions(-)