pgsql: formatting.c cleanup: Change several int fields to enums

formatting.c cleanup: Change several int fields to enums

This makes their purpose more self-documenting.

Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/6dd9d208-a3ed-49b5-b03d-8617261da973%40eisentraut.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/378212c68ab0f84fce2379c6e9cee750fec3c45b

Modified Files
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src/backend/utils/adt/formatting.c | 76 +++++++++++++++++++++++---------------
1 file changed, 46 insertions(+), 30 deletions(-)