node.c (rb_ast_new): imemo_ast is WB-unprotected

Previously imemo_ast was handled as WB-protected which caused a segfault
of the following code:

    # shareable_constant_value: literal
    M0 = {}
    M1 = {}
    ...
    M100000 = {}

My analysis is here: `shareable_constant_value: literal` creates many
Hash instances during parsing, and add them to node_buffer of imemo_ast.
However, the contents are missed because imemo_ast is incorrectly
WB-protected.

This changeset makes imemo_ast as WB-unprotected.

1 files changed, 1 insertions, 1 deletions

diff --git a/node.c b/node.c
index bef9d7bcbd..2392d5b8d1 100644
--- a/node.c
+++ b/node.c
@@ -1299,7 +1299,7 @@ rb_ast_t *
 rb_ast_new(void)
 {
     node_buffer_t *nb = rb_node_buffer_new();
-    rb_ast_t *ast = (rb_ast_t *)rb_imemo_new(imemo_ast, 0, 0, 0, (VALUE)nb);
+    rb_ast_t *ast = rb_imemo_ast_new((VALUE)nb);
     return ast;
 }