parse.y: duplicated when clause warning

* parse.y (case_args): moved "duplicated when clause" warning from
  compile phase, so that `ruby -wc` shows them.

1 files changed, 2 insertions, 0 deletions

diff --git a/node.h b/node.h
index f70cdc959a..57a0ea3932 100644
--- a/node.h
+++ b/node.h
@@ -384,6 +384,8 @@ typedef struct RNode {
 #define NODE_SPECIAL_NO_NAME_REST     ((NODE *)-1)
 #define NODE_NAMED_REST_P(node) ((node) != NODE_SPECIAL_NO_NAME_REST)
 
+VALUE rb_node_case_when_optimizable_literal(const NODE *const node);
+
 RUBY_SYMBOL_EXPORT_BEGIN
 
 typedef struct node_buffer_struct node_buffer_t;