Win64: please check my changes if you ran across them ;) But should be fine since no additional crashes were reported!

intern/guardedalloc/mmap_win.h

@@ -45,8 +45,10 @@
 
 #define MAP_FAILED ((void *)-1)
 
+#include "BLO_sys_types.h" // needed for intptr_t
+
 void *mmap(void *start, size_t len, int prot, int flags, int fd, off_t offset);
-long munmap(void *ptr, long size);
+intptr_t munmap(void *ptr, intptr_t size);
 
 #endif