patch 8.2.4055: Vim9: line break in expression causes v:errmsg to be fillec

Problem:    Vim9: line break in expression causes v:errmsg to be filled.
            (Yegappan Lakshmanan)
Solution:   Do not give an error when skipping over an expression.
diff --git a/src/userfunc.c b/src/userfunc.c
index a3ff38c..48f5890 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -1703,6 +1703,8 @@
     typval_T	argvars[MAX_FUNC_ARGS + 1];	// vars for arguments
     int		argcount = 0;		// number of arguments found
     int		vim9script = in_vim9script();
+    int		evaluate = evalarg == NULL
+			       ? FALSE : (evalarg->eval_flags & EVAL_EVALUATE);
 
     /*
      * Get the arguments.
@@ -1728,7 +1730,9 @@
 	{
 	    if (*argp != ',' && *skipwhite(argp) == ',')
 	    {
-		semsg(_(e_no_white_space_allowed_before_str_str), ",", argp);
+		if (evaluate)
+		    semsg(_(e_no_white_space_allowed_before_str_str),
+								    ",", argp);
 		ret = FAIL;
 		break;
 	    }
@@ -1739,7 +1743,8 @@
 	    break;
 	if (vim9script && !IS_WHITE_OR_NUL(argp[1]))
 	{
-	    semsg(_(e_white_space_required_after_str_str), ",", argp);
+	    if (evaluate)
+		semsg(_(e_white_space_required_after_str_str), ",", argp);
 	    ret = FAIL;
 	    break;
 	}
@@ -1778,7 +1783,7 @@
 
 	funcargs.ga_len -= i;
     }
-    else if (!aborting())
+    else if (!aborting() && evaluate)
     {
 	if (argcount == MAX_FUNC_ARGS)
 	    emsg_funcname(e_too_many_arguments_for_function_str_2, name);