patch 8.2.3895: Vim9: confusing error when using function() with a number

Problem:    Vim9: confusing error when using function() with a number.
Solution:   Check for a function or string argument.

src/evalfunc.c

@@ -3998,7 +3998,8 @@ common_function(typval_T *argvars, typval_T *rettv, int is_funcref)
     int		is_global = FALSE;
 
     if (in_vim9script()
-	    && (check_for_opt_list_arg(argvars, 1) == FAIL
+	    && (check_for_string_or_func_arg(argvars, 0) == FAIL
+		|| check_for_opt_list_arg(argvars, 1) == FAIL
 		|| (argvars[1].v_type != VAR_UNKNOWN
 		    && check_for_opt_dict_arg(argvars, 2) == FAIL)))
 	return;

src/testdir/test_vim9_builtin.vim

@@ -1352,6 +1352,8 @@ def Test_funcref()
 enddef
 
 def Test_function()
+  CheckDefExecAndScriptFailure(['function(123)'], 'E1256: String or function required for argument 1')
+
   CheckDefAndScriptFailure(['function("reverse", 2)'], ['E1013: Argument 2: type mismatch, expected list<any> but got number', 'E1211: List required for argument 2'])
   CheckDefAndScriptFailure(['function("reverse", [2], [1])'], ['E1013: Argument 3: type mismatch, expected dict<any> but got list<number>', 'E1206: Dictionary required for argument 3'])
 

src/version.c

@@ -749,6 +749,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3895,
 /**/
     3894,
 /**/