include stdint.h for uintptr_t

Due to a variation of compiling options, stdint.h might not be included in
debug.c, so it has to be defined explicitly.

src/debug.c

@@ -26,6 +26,7 @@
 
 #include "dmmlib_trace.h"
 #include <stdbool.h>
+#include <stdint.h>
 #include "dmmlib/dmmlib.h"
 #include "locks.h"