patch 8.2.2184: Vim9: no error when using "2" for a line number

Problem:    Vim9: no error when using "2" for a line number.
Solution:   Give an error message if the line number is invalid. (closes #7492)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index d40f89f..cf9c2c4 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -2615,6 +2615,8 @@
     else
     {
 	line = tv_get_lnum(argvars);
+	if (line < 0)
+	    semsg(_(e_invarg2), tv_get_string(&argvars[0]));
 	col = (long)tv_get_number_chk(&argvars[1], NULL);
 	if (argvars[2].v_type != VAR_UNKNOWN)
 	    coladd = (long)tv_get_number_chk(&argvars[2], NULL);