pgsql: Generate pg_stat_get_xact*() functions for relations using macro

Generate pg_stat_get_xact*() functions for relations using macros

This change replaces seven functions definitions by macros.

This is the same idea as 8018ffb or 83a1a1b, taking advantage of the
variable rename done in 8089517 for relation entries.

Author: Bertrand Drouvot
Discussion: https://postgr.es/m/631e3084-c5d9-8463-7540-fcff4674caa5@gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/850f4b4c8cab03a084ccc89245df061639ad1769

Modified Files
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src/backend/utils/adt/pgstatfuncs.c | 126 +++++++++---------------------------
1 file changed, 29 insertions(+), 97 deletions(-)