fix libfuzzer custom mutator and add introspection function

custom_mutators/libfuzzer/libfuzzer.cpp

@@ -6,6 +6,10 @@
 //#include "debug.h"
 #include "afl-fuzz.h"
 
+#ifdef  INTROSPECTION
+  const char *introspection_ptr;
+#endif
+
 afl_state_t *afl_struct;
 
 extern "C" size_t LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize);
@@ -133,6 +137,14 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf,
 
 }
 
+#ifdef  INTROSPECTION
+extern "C" const char* afl_custom_introspection(my_mutator_t *data) {
+
+  return introspection_ptr;
+
+}
+#endif
+
 /**
  * Deinitialize everything
  *