pgsql: Update relpages and reltuples estimates in stand-alone ANALYZE,

Log Message:
-----------
Update relpages and reltuples estimates in stand-alone ANALYZE, even if
there's no analyzable attributes or indexes. We also used to report 0 live
and dead tuples for such tables, which messed with autovacuum threshold
calculations.

This fixes bug #4812 reported by George Su. Backpatch back to 8.1.

Tags:
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REL8_2_STABLE

Modified Files:
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    pgsql/src/backend/commands:
        analyze.c (r1.101.2.1 -> r1.101.2.2)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/analyze.c?r1=1.101.2.1&r2=1.101.2.2)