Include windows.h rather than crtdbg.h to get STATUS_CONTROL_C_EXIT constant.
Moreover, include windows.h on Windows, not only when MSC is used.
--- /dev/null
+include of STATUS_CONTROL_C_EXIT without depending on MSC compiler
#if defined(HAVE_GETPID) && defined(HAVE_UNISTD_H)
# include <unistd.h> /* getpid() */
#endif
-#ifdef _MSC_VER
-# include <crtdbg.h> /* STATUS_CONTROL_C_EXIT */
+#ifdef MS_WINDOWS
+# include <windows.h> /* STATUS_CONTROL_C_EXIT */
#endif
/* End of includes for exit_sigint() */