Fixes for Windows.

src/SignalHandling.hpp

@@ -1,9 +1,12 @@
 #ifndef ARBUTILS_SIGNALHANDLING_HPP
 #define ARBUTILS_SIGNALHANDLING_HPP
+#if !WINDOWS
 #if PRETTYTRACES
 #define BACKWARD_HAS_DW 1
 #endif
 #include "../extern/backward.hpp"
+#endif
+
 #include "Exception.hpp"
 
 // Sourced from https://github.com/bombela/backward-cpp/blob/master/backward.hpp#L3849