rework structure

benchmarks/dhrystone/dhry_stubs.c

@@ -0,0 +1,22 @@
+#include "platform.h"
+
+/* The functions in this file are only meant to support Dhrystone on an
+ * embedded RV32 system and are obviously incorrect in general. */
+
+long time(void)
+{
+  return get_timer_value();
+}
+
+// set the number of dhrystone iterations
+void __wrap_scanf(const char* fmt, int* n)
+{
+  *n = 200000;
+}
+
+extern volatile uint32_t tohost;
+
+void __wrap_exit(int n){
+      tohost = 0x1;
+      for (;;);
+}