simplifying an example module, to try to diagnose the mac build error.

runtime/sample.c

@@ -1,6 +1,4 @@
-#include <stdint.h>
+extern void print(char *variable_name, unsigned long long value);
-
-void print(char *variable_name, uint64_t value);
 
 void gogogo() {
     print("x", 4);