pgsql: Use aux process resource owner in walsender

Use aux process resource owner in walsender

AIO will need a resource owner to do IO. Right now we create a resowner
on-demand during basebackup, and we could do the same for AIO. But it seems
easier to just always create an aux process resowner.

Reviewed-by: Heikki Linnakangas <hlinnaka(at)iki(dot)fi>
Reviewed-by: Noah Misch <noah(at)leadboat(dot)com>
Discussion: https://postgr.es/m/1f6b50a7-38ef-4d87-8246-786d39f46ab9@iki.fi

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/57f37024712702350b714cf64215077f1d75c568

Modified Files
--------------
src/backend/backup/basebackup.c | 8 ++++---
src/backend/replication/walsender.c | 44 +++++++------------------------------
src/include/replication/walsender.h | 1 -
3 files changed, 13 insertions(+), 40 deletions(-)