system/FileDescriptor: add Open() overload with wchar_t path

src/system/FileDescriptor.cxx

@@ -74,6 +74,17 @@ FileDescriptor::Open(const char *pathname, int flags, mode_t mode) noexcept
 	return IsDefined();
 }
 
+#ifdef _WIN32
+
+bool
+FileDescriptor::Open(const wchar_t *pathname, int flags, mode_t mode) noexcept
+{
+	fd = ::_wopen(pathname, flags | O_NOCTTY | O_CLOEXEC, mode);
+	return IsDefined();
+}
+
+#endif
+
 bool
 FileDescriptor::OpenReadOnly(const char *pathname) noexcept
 {

src/system/FileDescriptor.hxx

@@ -43,6 +43,10 @@
 #include <signal.h>
 #endif
 
+#ifdef _WIN32
+#include <wchar.h>
+#endif
+
 /**
  * An OO wrapper for a UNIX file descriptor.
  *
@@ -97,6 +101,11 @@ public:
 	}
 
 	bool Open(const char *pathname, int flags, mode_t mode=0666) noexcept;
+
+#ifdef _WIN32
+	bool Open(const wchar_t *pathname, int flags, mode_t mode=0666) noexcept;
+#endif
+
 	bool OpenReadOnly(const char *pathname) noexcept;
 
 #ifndef WIN32