Integrate GistTranslateCompareType() into IndexAmTranslateCompareType()
This turns GistTranslateCompareType() into a callback function of the
gist index AM instead of a standalone function. The existing callers
are changed to use IndexAmTranslateCompareType(). This then makes
that code not hardc
Add data for WAL in pg_stat_io and backend statistics
This commit adds WAL IO stats to both pg_stat_io view and per-backend IO
statistics (pg_stat_get_backend_io()). This change is possible since
f92c854cf406, as WAL IO is not counted in blocks in some code paths
where its stats data is measured