curl

curl_config.h

Generated with

./configure \
	--disable-pop3 \
	--disable-smb \
	--disable-smtp \
	--with-ca-fallback \
	--without-ca-bundle \
	CPPFLAGS='-I/src/oasis/out/pkg/libressl/include -I/src/oasis/out/pkg/zlib/include' \
	LDFLAGS='-L/src/oasis/out/pkg/libressl -L/src/oasis/out/pkg/zlib/lib' \
	LIBS=/src/oasis/out/pkg/openbsd/libbsd.a

There are a number of non-standard definitions, but they don't seem to be architecture-specific except for

SIZEOF_CURL_OFF_T
SIZEOF_INT
SIZEOF_LONG
SIZEOF_LONG_LONG
SIZEOF_OFF_T
SIZEOF_SHORT
SIZEOF_SIZE_T
SIZEOF_TIME_T

Perhaps all or most of these can eliminated using standard C99 features.