[COMMITTERS] pgsql: Fix locale dependency in new ecpg test case.

Fix locale dependency in new ecpg test case.

Force sorting in "C" locale so that the output ordering doesn't vary,
per buildfarm.

In passing, add missing .gitignore entries.

Discussion: https://postgr.es/m/0975f4bb-5dee-c33c-b719-3ce44026d397@chrullrich.net

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/aae62278e167623bfac9fd50d1242d8e72208b0c

Modified Files
--------------
.../test/expected/preproc-whenever_do_continue.c   |  4 ++--
.../expected/preproc-whenever_do_continue.stderr   | 24 +++++++++++-----------
.../expected/preproc-whenever_do_continue.stdout   |  2 +-
src/interfaces/ecpg/test/preproc/.gitignore        |  2 ++
.../ecpg/test/preproc/whenever_do_continue.pgc     |  2 +-
5 files changed, 18 insertions(+), 16 deletions(-)