arguments work properly - and the option is not harmful for the rest of the
curl build either!

done in one single function CURL_CHECK_FUNC_GETNAMEINFO which
will only define HAVE_GETNAMEINFO if the function has been found
AND the type of its arguments has been properly been detected

proper types to use for getnameinfo args

proper types to use for getnameinfo args

target use calling convention WSAAPI for getnameinfo() prototype.
Checking type DWORD as argument 4 and 6 of getnameinfo not needed.

following order: 'struct sockaddr *' 'const struct sockaddr *' 'void *'.

Avoid breaking configure due to CURL_FUNC_GETNAMEINFO_ARGTYPES failure, since at this point nothing depends on it.

justify checking for socklen_t in more than one function, the code
used to find a valid socklen_t replacement is simplified back. The
only function that will be used to find a socklen_t replacement is
getpeername, as it has been since revision 1.4 of curl/acinclude.m4

CURL_FUNC_GETNAMEINFO_ARGTYPES now also checks first argument.
All related changes taken to cares configuration scripts.

valid windows.h winsock.h winsock2.h and ws2tcpip.h
header files:
CURL_CHECK_HEADER_WINDOWS
CURL_CHECK_HEADER_WINSOCK
CURL_CHECK_HEADER_WINSOCK2
CURL_CHECK_HEADER_WS2TCPIP

Determine the correct type to be passed to four of the `getnameinfo' function's arguments, and define those types in `GETNAMEINFO_TYPE_ARG2', `GETNAMEINFO_TYPE_ARG46', and `GETNAMEINFO_TYPE_ARG7'.

recent gcc versions give far too many false positives for this to be valuable

variable declarations.

when looking for the prototype

times, like on my HP-UX 10.20 tests. And then lib/strerror.c badly assumed
the glibc version if the posix define wasn't set (since it _had_ found a
strerror_r).

least it should no longer cause a compiler error. However, it does not have
AI_NUMERICHOST so we cannot getaddrinfo() any numerical addresses with it (we
use that for FTP PORT/EPRT)! So, I modified the configure check that checks if
the getaddrinfo() is working, to use AI_NUMERICHOST since then it'll fail on
AIX 4.3 and it will automatically build with IPv6 support disabled.

to survive without it if not found. AIX 4.3 targetted adjustment.