Fix building with Perl on Windows with MingW. (James Vega)
diff --git a/src/if_perl.xs b/src/if_perl.xs
index 636e704..a3dc4fe 100644
--- a/src/if_perl.xs
+++ b/src/if_perl.xs
@@ -89,7 +89,7 @@
#if defined(DYNAMIC_PERL) || defined(PROTO)
#ifndef DYNAMIC_PERL /* just generating prototypes */
-#ifdef _MSWIN
+#ifdef WIN3264
typedef int HANDLE;
#endif
typedef int XSINIT_t;
@@ -97,7 +97,7 @@
typedef int perl_key;
#endif
-#ifndef _MSWIN
+#ifndef WIN3264
#include <dlfcn.h>
#define HANDLE void*
#define PERL_PROC void*