[COMMITTERS] pgsql: Further tweaks to compiler flags for PL/Perl on Windows.

Further tweaks to compiler flags for PL/Perl on Windows.

It now emerges that we can only rely on Perl to tell us we must use
-D_USE_32BIT_TIME_T if it's Perl 5.13.4 or later.  For older versions,
revert to our previous practice of assuming we need that symbol in
all 32-bit Windows builds.  This is not ideal, but inquiring into
which compiler version Perl was built with seems far too fragile.
In any case, we had not previously had complaints about these old
Perl versions, so let's assume this is Good Enough.  (It's still
better than the situation ante commit 5a5c2feca, in that at least
the effects are confined to PL/Perl rather than the whole PG build.)

Back-patch to all supported versions, like 5a5c2feca and predecessors.

Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com

Branch
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REL9_4_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/4f862351d20bb1c592aa76cfa692e4e8c51b4123

Modified Files
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src/tools/msvc/Mkvcbuild.pm | 12 ++++++++++++
1 file changed, 12 insertions(+)