Jeff King authored Mar 06, 2019 and Junio C Hamano committed Mar 07, 2019

Our compat/bswap.h lacks the usual preprocessor guards against multiple
inclusion. This usually isn't an issue since it only gets included from
git-compat-util.h, which has its own guards. But it would produce
redeclaration errors if any file included it separately.

Our hdr-check target would complain about this, except that it currently
skips items in compat/ entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>