pgsql: Report incompatible roles in pg_upgrade checking

Report incompatible roles in pg_upgrade checking

When checking for roles with a pg_ prefix in <= 9.5 servers, report
all found roles in a text file as how other checks are done instead
of just reporting that they exist. Rolenames are printed with their
Oids to match other reports.

Author: Daniel Gustafsson <daniel(at)yesql(dot)se>
Reviewed-by: Bruce Momjian <bruce(at)momjian(dot)us>
Reviewed-by: Michael Paquier <michael(at)paquier(dot)xyz>
Discussion: https://postgr.es/m/4BB2735C-C347-4CF7-AFB1-8573BE930066@yesql.se

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c76da690ba141160d23cae715922932b7efa5b23

Modified Files
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src/bin/pg_upgrade/check.c | 39 ++++++++++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 7 deletions(-)