patch 9.0.0335: checks for Dictionary argument often give a vague error

Problem:    Checks for Dictionary argument often give a vague error message.
Solution:   Give a useful error message. (Yegappan Lakshmanan, closes #11009)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 92c3269..be1b2e7 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -3277,11 +3277,9 @@
 
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
-	if (argvars[2].v_type != VAR_DICT)
-	{
-	    emsg(_(e_dictionary_required));
+	if (check_for_dict_arg(argvars, 2) == FAIL)
 	    return;
-	}
+
 	selfdict = argvars[2].vval.v_dict;
     }
 
@@ -4501,9 +4499,8 @@
 		arg_idx = 1;
 	    if (dict_idx > 0)
 	    {
-		if (argvars[dict_idx].v_type != VAR_DICT)
+		if (check_for_dict_arg(argvars, dict_idx) == FAIL)
 		{
-		    emsg(_(e_expected_dict));
 		    vim_free(name);
 		    goto theend;
 		}
@@ -9291,15 +9288,9 @@
     dictitem_T	*di;
     char_u	*csearch;
 
-    if (in_vim9script() && check_for_dict_arg(argvars, 0) == FAIL)
+    if (check_for_dict_arg(argvars, 0) == FAIL)
 	return;
 
-    if (argvars[0].v_type != VAR_DICT)
-    {
-	emsg(_(e_dictionary_required));
-	return;
-    }
-
     if ((d = argvars[0].vval.v_dict) != NULL)
     {
 	csearch = dict_get_string(d, "char", FALSE);
@@ -9637,11 +9628,8 @@
 	return;
 
     // second argument: dict with items to set in the tag stack
-    if (argvars[1].v_type != VAR_DICT)
-    {
-	emsg(_(e_dictionary_required));
+    if (check_for_dict_arg(argvars, 1) == FAIL)
 	return;
-    }
     d = argvars[1].vval.v_dict;
     if (d == NULL)
 	return;