Change WIN32 to _WIN32 in configure.in, too.

configure.in

@@ -224,12 +224,12 @@ AC_ARG_WITH(tor-group,
 AC_SUBST(TORGROUP)
 
 
-dnl If WIN32 is defined and non-zero, we are building for win32
+dnl If _WIN32 is defined and non-zero, we are building for win32
 AC_MSG_CHECKING([for win32])
 AC_RUN_IFELSE([AC_LANG_SOURCE([
 int main(int c, char **v) {
-#ifdef WIN32
-#if WIN32
+#ifdef _WIN32
+#if _WIN32
   return 0;
 #else
   return 1;
@@ -246,7 +246,7 @@ bwin32=cross; AC_MSG_RESULT([cross])
 if test "$bwin32" = cross; then
 AC_MSG_CHECKING([for win32 (cross)])
 AC_COMPILE_IFELSE([AC_LANG_SOURCE([
-#ifdef WIN32
+#ifdef _WIN32
 int main(int c, char **v) {return 0;}
 #else
 #error
@@ -377,19 +377,19 @@ if test "$enable_static_libevent" = "yes"; then
 fi
 
 TOR_SEARCH_LIBRARY(libevent, $trylibeventdir, [-levent $STATIC_LIBEVENT_FLAGS $TOR_LIB_WS32], [
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #endif
 #include <stdlib.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <event.h>], [
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #endif
 void exit(int); void *event_init(void);],
     [
-#ifdef WIN32
+#ifdef _WIN32
 {WSADATA d; WSAStartup(0x101,&d); }
 #endif
 event_init(); exit(0);