Fix compilation on Windows

xs/Build.PL

@@ -23,7 +23,8 @@ my $build = Module::Build::WithXSpp->new(
     )},
     # _GLIBCXX_USE_C99 : to get the long long type for g++
     # HAS_BOOL         : stops Perl/lib/CORE/handy.h from doing "#  define bool char" for MSVC
-    extra_compiler_flags => [qw(-D_GLIBCXX_USE_C99 -DHAS_BOOL)],
+    # NOGDI            : prevents inclusion of wingdi.h which defines functions Polygon() and Polyline() in global namespace
+    extra_compiler_flags => [qw(-D_GLIBCXX_USE_C99 -DHAS_BOOL -DNOGDI)],
     
     # Provides extra C typemaps that are auto-merged
     extra_typemap_modules => {

xs/src/myinit.h

@@ -1,6 +1,9 @@
 #ifndef _myinit_h_
 #define _myinit_h_
 
+// this needs to be included early for MSVC (listing it in Build.PL is not enough)
+#include <ostream>
+
 extern "C" {
 #include "EXTERN.h"
 #include "perl.h"