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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REL8_3_STABLE

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=9fe5a62a1711b939643f5d1faeba1d336f990184

Modified Files
--------------
configure                           |   21 +++++++++++++++++++++
configure.in                        |    7 +++++++
src/backend/postmaster/postmaster.c |    5 +++--
3 files changed, 31 insertions(+), 2 deletions(-)