pgsql: Make some use of anonymous unions [pg_locale_t]

Make some use of anonymous unions [pg_locale_t]

Make some use of anonymous unions, which are allowed as of C11, as
examples and encouragement for future code, and to test compilers.

This commit changes the pg_locale_t type.

Reviewed-by: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Discussion: https://www.postgresql.org/message-id/flat/f00a9968-388e-4f8c-b5ef-5102e962d997%40eisentraut.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4b7e6c73b0df3384345052616727a25505db5fcb

Modified Files
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src/backend/utils/adt/pg_locale_builtin.c | 20 ++++-----
src/backend/utils/adt/pg_locale_icu.c | 18 ++++----
src/backend/utils/adt/pg_locale_libc.c | 70 +++++++++++++++----------------
src/include/utils/pg_locale.h | 2 +-
4 files changed, 55 insertions(+), 55 deletions(-)