pgsql: Limit to_tsvector_byid's initial array allocation to something s

Limit to_tsvector_byid's initial array allocation to something sane.

The initial estimate of the number of distinct ParsedWords is just
that: an estimate.  Don't let it exceed what palloc is willing to
allocate.  If in fact we need more entries, we'll eventually fail
trying to enlarge the array.  But if we don't, this allows success on
inputs that currently draw "invalid memory alloc request size".

Per bug #18080 from Uwe Binder.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/18080-d5c5e58fef8c99b7@postgresql.org

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/4a81ed29d3c956ad11354c0dc4514f5af4a0d8d7

Modified Files
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src/backend/tsearch/to_tsany.c | 2 ++
1 file changed, 2 insertions(+)