`AC_CHECK_FUNCS` can not properly check `getaddrinfo` because this
function requires some special headers on mingw.
Using `AC_CHECK_DECL` can effectively solve this issue.
Same for
- getnameinfo
- getprotobynumber
- getservbyname
- inet_ntop
- inet_pton
Since commit 506df426dbeb0187bbd3654bd286b4100628fb16, OPENSSL_INCS is
added to CPPFLAGS without any white space, as a result openssl detection
fails on:
configure:10395: checking openssl/ssl.h usability
configure:10395: /home/fabrice/buildroot-test/buildroot/output/host/bin/riscv32-linux-gcc -c -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -Wall -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64-I/home/fabrice/buildroot-test/buildroot/output/host/bin/../riscv32-buildroot-linux-gnu/sysroot/usr/include conftest.c >&5
<command-line>:0:0: warning: "_FILE_OFFSET_BITS" redefined
<command-line>:0:0: note: this is the location of the previous definition
<command-line>:0:23: error: division by zero in #if
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>