do fail interactions inside wasm module + unify host modules + fix cored module

targets/lib.h

@@ -4,6 +4,10 @@
 #define INLINE __attribute__((always_inline)) inline
 #define NOINLINE __attribute__((noinline))
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 // Mark start of injection
 void NOINLINE fail_start_trace(void);
 // Mark end of injection
@@ -16,4 +20,8 @@ void NOINLINE fail_marker_negative(void);
 // invalid code
 void NOINLINE fail_marker_detected(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif