pgsql: Fix up getopt() reset management so it works on recent mingw.

Fix up getopt() reset management so it works on recent mingw.

The mingw people don't appear to care about compatibility with non-GNU
versions of getopt, so force use of our own copy of getopt on Windows.
Also, ensure that we make use of optreset when using our own copy.

Per report from Andrew Dunstan.  Back-patch to all versions supported
on Windows.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=5cdd65f3241ce10c66953228daef60df7b3966d1

Modified Files
--------------
configure                           |   25 +++++++++++++++++++++----
configure.in                        |   21 ++++++++++++++-------
src/backend/postmaster/postmaster.c |    5 +++--
src/backend/tcop/postgres.c         |    5 +++--
4 files changed, 41 insertions(+), 15 deletions(-)