pgsql: Have config_sspi_auth() permit IPv6 localhost connections.

Have config_sspi_auth() permit IPv6 localhost connections.

Windows versions later than Windows Server 2003 map "localhost" to ::1.
Account for that in the generated pg_hba.conf, fixing another oversight
in commit f6dc6dd5ba54d52c0733aaafc50da2fbaeabb8b0.  Back-patch to 9.0,
like that commit.

David Rowley and Noah Misch

Branch
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REL9_0_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/a99ec2b925785311bcb879c10adba906353004a0

Modified Files
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src/test/regress/pg_regress.c |   26 ++++++++++++++++++++++++++
src/tools/msvc/Mkvcbuild.pm   |    3 +++
2 files changed, 29 insertions(+)