patch 8.2.0820: Vim9: function type isn't set until compiled

Problem:    Vim9: function type isn't set until compiled.
Solution:   Set function type early.
diff --git a/src/userfunc.c b/src/userfunc.c
index f29a7b5..bc92c2a 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -3284,6 +3284,9 @@
 	is_export = FALSE;
     }
 
+    if (eap->cmdidx == CMD_def)
+	set_function_type(fp);
+
     goto ret_free;
 
 erret: