pgsql: Fix build of Perl-using modules of Windows

Fix build of Perl-using modules of Windows

Commit f14413b684d57211068ee56ee04695efcc87a23a broke the build of
Perl-using modules on Windows.

Perl might have its own definitions of uid_t and gid_t, so we hide
ours, but then we can't use ours in our header files such as port.h
which don't see the Perl definition.

Hide our definition of getpeereid() on Windows in Perl-using modules,
using PLPERL_HAVE_UID_GID define. That means we can't portably use
getpeeruid() is such modules right now, but there is no need anyway.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/502423180a8cc9214861bffcb8405a42f146f160

Modified Files
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src/include/port.h | 3 +++
1 file changed, 3 insertions(+)