pgsql: Fix collation exposed for scalar function in FROM.

Fix collation exposed for scalar function in FROM.

One code path in addRangeTableEntryForFunction() neglected to assign
a collation to the tupdesc entry it constructs (which is a bit odd
considering the other path did do so). This didn't matter before commit
5815696bc, because nothing would look at the type data in this tupdesc;
but now it does.

While at it, make sure we assign the correct typmod as well. Most
function expressions don't have a determinate typmod, but some do.

Per buildfarm, which showed failures in non-C collations, a case
I'd not thought to test for this patch :-(

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4d02eb017e3c1268762fd1a10ec3c569515c047d

Modified Files
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src/backend/parser/parse_relation.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)