Обсуждение: pgsql: Test honestly for .

Test honestly for <sys/signalfd.h>.

Commit 6a2a70a02 supposed that any platform having <sys/epoll.h>
would also have <sys/signalfd.h>.  It turns out there are still a
few people using platforms where that's not so, so we'd better make
a separate configure probe for it.  But since it took this long to
notice, I'm content with the decision to not have a separate code
path for epoll-only machines; we'll just fall back to using poll()
for these stragglers.

Per gripe from Gabriela Serventi.  Back-patch to v14 where this
code came in.

Discussion: https://postgr.es/m/CAHOHWE-JjJDfcYuLAAEO7Jk07atFAU47z8TzHzg71gbC0aMy=g@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c5f5b4dd4b5ccecd193550530ff483f16f95746b

Modified Files
--------------
configure                       | 2 +-
configure.ac                    | 1 +
src/backend/storage/ipc/latch.c | 9 ++++-----
src/include/pg_config.h.in      | 3 +++
src/tools/msvc/Solution.pm      | 1 +
5 files changed, 10 insertions(+), 6 deletions(-)