a test case about unhandled cases(show buggy compiler impl)

tests/cram/test_dirs/match.t/run.t

@@ -164,3 +164,65 @@
 
   $ ./test_match.fun.out
   19981022
+
+  $ $FF test_unhandled.fun
+
+  $ cat test_unhandled.fun.cpp
+
+  #include "fun_rt.hpp"
+  #include <stdio.h>
+  #include <stdexcept>
+
+  ff_obj_t main_1__fn(ff_fvs_t fvs_1);
+
+  ff_obj_t main_1__fn(ff_fvs_t fvs_1)
+  {
+  	ff_obj_t mod_11;
+  	ff_obj_t __10;
+  	ff_obj_t is_true_9;
+  	ff_obj_t temp_8;
+  	ff_obj_t __7;
+  	ff_obj_t temp_6;
+  	ff_obj_t app_res_5;
+  	ff_obj_t constr0_4;
+  	ff_obj_t match_res_3;
+  	ff_obj_t println_str_2;
+  	println_str_2 = ff_builtin_println_str;
+  	do
+  	{
+  		constr0_4 = ff_make_constr_no_payload(0);
+  		if(ff_match_constr(1, constr0_4))
+  		{
+  			temp_6 =
+  				ff_make_str("internal error, this should never matched")
+  				;
+  			app_res_5 = ff_apply_generic(println_str_2, temp_6);
+  			match_res_3 = app_res_5;
+  			break;
+  		}
+  	}
+  	while(0);
+  	__7 = match_res_3;
+  	temp_8 = ff_make_int(0);
+  	is_true_9 = ff_assert(temp_8);
+  	__10 = is_true_9;
+  	mod_11 = ff_make_mod_obj(3, {"println_str", "_", "_"}, {println_str_2,
+  		__7, __10});
+  	return mod_11;
+  }
+
+
+  int main()
+  {
+    try
+    {
+      main_1__fn(nullptr);
+    }
+    catch (const std::runtime_error& error)
+    {
+      printf("Runtime error: %s", error.what());
+    }
+  }
+
+  $ ./test_unhandled.fun.out
+  Runtime error: Assertion failed!

tests/cram/test_dirs/match.t/test_unhandled.fun

@@ -0,0 +1,11 @@
+external println_str : string -> unit = "ff_builtin_println_str"
+
+type t =
+  | Cons1
+  | Cons2
+
+let _ =
+  match Cons1 with
+  | Cons2 -> println_str "internal error, this should never matched"
+
+let _ = assert false