pgsql: pg_regress: Observe TMPDIR

pg_regress: Observe TMPDIR

Put the temporary socket directory under TMPDIR, if that environment
variable is set, instead of the hardcoded /tmp.

This allows running the tests if there is no /tmp at all (for example
on Windows, although running the tests with Unix-domain sockets is not
enabled on Windows yet). We also use TMPDIR everywhere else /tmp is
hardcoded, so this makes the behavior consistent.

Reviewed-by: Andrew Dunstan <andrew(dot)dunstan(at)2ndquadrant(dot)com>
Discussion: https://www.postgresql.org/message-id/flat/54bde68c-d134-4eb8-5bd3-8af33b72a010(at)2ndquadrant(dot)com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/9cedb1666051516c2763bb0ae4ace583cd26b141

Modified Files
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src/test/regress/pg_regress.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)