pgsql: Support tab-complete for TRUNCATE on foreign tables.

Support tab-complete for TRUNCATE on foreign tables.

Commit 8ff1c94649 extended TRUNCATE command so that it can also truncate
foreign tables. But it forgot to support tab-complete for TRUNCATE on
foreign tables. That is, previously tab-complete for TRUNCATE displayed
only the names of regular tables.

This commit improves tab-complete for TRUNCATE so that it displays also
the names of foreign tables.

Author: Fujii Masao
Reviewed-by: Bharath Rupireddy
Discussion: https://postgr.es/m/551ed8c1-f531-818b-664a-2cecdab99cd8@oss.nttdata.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/81e094bdfdd6cf6568cba2b25eea9876daceaacb

Modified Files
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src/bin/psql/tab-complete.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)