patch 9.1.0270: a few minor issues to fix

The following is a collection of some small fixes:

- Problem:  Vim9: funcref pointer pt leaks, when function is not found
  Solution: Free funcref pointer in case of error (fixes: #14254)

- Problem:  memory leak of crypt state pointer allocation fails
  Solution: free crypt state pointer properly (fixes: #14253)

- Problem:  Vim9: Leaking memory when compiling dict fails
  Solution: Free the memory in case of error (fixes: #14252)

- Problem:  Coverity complains about derefencing obj_members pointer
            (after v9.1.0261)
  Solution: Verify that obj_members ptr is non-null before accessing it

  References: https://scan5.scan.coverity.com/#/project-view/41242/10101?selectedIssue=1596133

closes: #14412

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/vim9expr.c

@@ -1561,7 +1561,10 @@ compile_dict(char_u **arg, cctx_T *cctx, ppconst_T *ppconst)
     if (d == NULL)
 	return FAIL;
     if (generate_ppconst(cctx, ppconst) == FAIL)
+    {
+	dict_unref(d);
 	return FAIL;
+    }
     for (;;)
     {
 	char_u	    *key = NULL;