pgsql: Use version for builtin collations.

Use version for builtin collations.

Given that the version field already exists, there's little reason not
to use it. Suggestion from Peter Eisentraut.

Discussion: https://postgr.es/m/613c120a-5413-4fa7-a501-6590eae558f8@eisentraut.org
Reviewed-by: Peter Eisentraut

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/46a44dc372033da9bd8b9840711e560c9d73e768

Modified Files
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src/backend/utils/adt/pg_locale.c    | 14 ++++++++++++--
src/include/catalog/catversion.h     |  2 +-
src/include/catalog/pg_collation.dat |  4 ++--
3 files changed, 15 insertions(+), 5 deletions(-)