pgsql: Add information about WAL buffers full to VACUUM/ANALYZE (VERBOS

Add information about WAL buffers full to VACUUM/ANALYZE (VERBOSE)

This commit adds the information about the number of times WAL buffers
have been full to the logs generated by VACUUM/ANALYZE (VERBOSE) and in
the logs generated by autovacuum, complementing the existing information
stored by WalUsage.

This is the last part of the backend code where the value of
wal_buffers_full can be reported, similarly to all the other fields of
WalUsage.  320545bfcfee and ce5bcc4a9f26 have done the same for EXPLAIN
and pgss.

Author: Bertrand Drouvot
Reviewed-by: Ilia Evdokimov
Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6a8a7ce476bd5f042999a04a0d767b38ea6faec0

Modified Files
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src/backend/access/heap/vacuumlazy.c | 5 +++--
src/backend/commands/analyze.c       | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)