pgsql: Install the "posixrules" timezone link in MSVC builds.

Install the "posixrules" timezone link in MSVC builds.

Somehow, we'd missed ever doing this. The consequences aren't too
severe: basically, the timezone library would fall back on its hardwired
notion of the DST transition dates to use for a POSIX-style zone name,
rather than obeying US/Eastern which is the intended behavior. The net
effect would only be to obey current US DST law further back than it
ought to apply; so it's not real surprising that nobody noticed.

David Rowley, per report from Amit Kapila

Discussion: https://postgr.es/m/CAA4eK1LC7CaNhRAQ__C3ht1JVrPzaAXXhEJRnR5L6bfYHiLmWw@mail.gmail.com

Branch
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REL9_6_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/f754728170b7bd4624902bf0129a1c88f910ac3c

Modified Files
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src/tools/msvc/Install.pm | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)