patch 8.2.1427: Vim9: cannot use a range with marks in :def function

Problem:    Vim9: cannot use a range with marks in :def function.
Solution:   Parse range after colon. (closes #6686)
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 88108f4..dfcff50 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -6567,7 +6567,7 @@
 	 * 'text'->func() should not be confused with 'a mark
 	 */
 	cmd = ea.cmd;
-	if (*cmd != '\'')
+	if (*cmd != '\'' || starts_with_colon)
 	{
 	    ea.cmd = skip_range(ea.cmd, NULL);
 	    if (ea.cmd > cmd && !starts_with_colon)