pgsql: Fix handling of expecteddir in pg_regress

Fix handling of expecteddir in pg_regress

Commit c855872074b introduced a new parameter to pg_regress to set
the directory where to look for expected files, but accidentally
only implemented it for when compiling pg_regress for ECPG tests.
Fix by adding support for the parameter to the main regression test
compilation of pg_regress as well.

Backpatch to v16 where --expecteddir was introduced.

Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Discussion: https://postgr.es/m/CAO6_Xqq5yKJHcJsq__LPcKwSY0XHRqVERNWGxx5ttNXXj7+W=A@mail.gmail.com
Backpatch-through: 16

Branch
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REL_16_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/56432629999736b5cdd6fa8e56545d8ac5da281f

Modified Files
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src/test/regress/pg_regress_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)