now sets a type for in_addr_t even if it isn't found in the #include files

         # Systems have either "struct sockaddr *" or

         # "void *" as the second argument to getpeername

         curl_cv_in_addr_t_equiv=

         for arg2 in "struct sockaddr" void; do

         for t in int size_t unsigned long "unsigned long"; do

            AC_TRY_COMPILE([

               #include <sys/types.h>

               #include <sys/socket.h>

               #include <arpa/inet.h>

            ],[

                  $arg data = inet_addr ("1.2.3.4");

               $t data = inet_addr ("1.2.3.4");

            ],[

               curl_cv_in_addr_t_equiv="$t"

               break

            ])

         done

         done

         if test "x$curl_cv_in_addr_t_equiv" = x; then

            AC_MSG_ERROR([Cannot find a type to use in place of in_addr_t])