Don't set T_TYPES of NODE

T_TYPES was needed once Ripper jumbled NODEs and other type
objects. However such hack was already removed.
Therefore don't need to set T_TYPES of NODE.

node.c

@@ -15,7 +15,6 @@
 #include "node.h"
 #include "rubyparser.h"
 #include "internal/parse.h"
-#define T_NODE 0x1b
 
 #else
 
@@ -87,16 +86,10 @@ rb_node_buffer_new(void)
 typedef void node_itr_t(rb_ast_t *ast, void *ctx, NODE *node);
 static void iterate_node_values(rb_ast_t *ast, node_buffer_list_t *nb, node_itr_t * func, void *ctx);
 
-/* Setup NODE structure.
- * NODE is not an object managed by GC, but it imitates an object
- * so that it can work with `RB_TYPE_P(obj, T_NODE)`.
- * This dirty hack is needed because Ripper jumbles NODEs and other type
- * objects.
- */
 void
 rb_node_init(NODE *n, enum node_type type)
 {
-    RNODE(n)->flags = T_NODE;
+    RNODE(n)->flags = 0;
     nd_init_type(RNODE(n), type);
     RNODE(n)->nd_loc.beg_pos.lineno = 0;
     RNODE(n)->nd_loc.beg_pos.column = 0;

rubyparser.h

@@ -1178,7 +1178,7 @@ typedef struct RNode_ERROR {
 #define RNODE_ENCODING(node) ((struct RNode_ENCODING *)(node))
 
 /* FL     : 0..4: T_TYPES, 5: KEEP_WB, 6: PROMOTED, 7: FINALIZE, 8: UNUSED, 9: UNUSED, 10: EXIVAR, 11: FREEZE */
-/* NODE_FL: 0..4: T_TYPES, 5: KEEP_WB, 6: PROMOTED, 7: NODE_FL_NEWLINE,
+/* NODE_FL: 0..4: UNUSED,  5: UNUSED,  6: UNUSED,   7: NODE_FL_NEWLINE,
  *          8..14: nd_type,
  *          15..: nd_line
  */