Enable tests for invalid documents starting with n (#94)

* Enable tests for invalid documents starting with n

* Add test for invalid document with trailing text

Oddly, `null trailing` gives an error, but `nully trailing` does not

* Add workaround for scalar document is_null bug

For now, we can just manually throw the exception until the next
simdjson bugfix release: simdjson/simdjson#2258

Author: tobil4sk

jsonexamples/invalid/nully_trailing.json

@@ -0,0 +1 @@
+nully trailing

spec/compile_spec.lua

@@ -108,10 +108,11 @@ end
 
 local invalid_files = {
     "bool_trailing.json",
+    "nully_trailing.json",
     "nil_token.json",
-    -- "nil_token_scalar.json",
+    "nil_token_scalar.json",
     "nully_token.json",
-    -- "nully_token_scalar.json"
+    "nully_token_scalar.json"
 }
 
 describe("Make sure invalid files are not accepted", function()

src/luasimdjson.cpp

@@ -124,6 +124,9 @@ void convert_ondemand_element_to_table(lua_State *L, T& element) {
       // calling is_null().value() will trigger an exception if the value is invalid
       if (element.is_null().value()) {
         lua_pushlightuserdata(L, NULL);
+      } else {
+        // workaround for simdjson 3.10.1
+        throw simdjson_error(INCORRECT_TYPE);
       }
       break;
   }