Revert "Revert "[ruby/prism] Change ScopeNode to point to previous ScopeNode""

This reverts commit fd87372a74.

prism/node.h

@@ -33,10 +33,17 @@ PRISM_EXPORTED_FUNCTION const char * pm_node_type_to_str(pm_node_type_t node_typ
 // declare them here to avoid generating them.
 typedef struct pm_scope_node {
     pm_node_t base;
+    struct pm_scope_node *previous;
     pm_node_t *ast_node;
     struct pm_parameters_node *parameters;
     pm_node_t *body;
     pm_constant_id_list_t locals;
+    pm_parser_t *parser;
+
+    // We don't have the CRuby types ID and st_table within Prism
+    // so we use void *
+    void *constants; // ID *constants
+    void *index_lookup_table; // st_table *index_lookup_table
 } pm_scope_node_t;
 
 #endif // PRISM_NODE_H

prism/prism.c

@@ -654,14 +654,22 @@ pm_arguments_validate_block(pm_parser_t *parser, pm_arguments_t *arguments, pm_b
 
 // Generate a scope node from the given node.
 void
-pm_scope_node_init(pm_node_t *node, pm_scope_node_t *scope) {
+pm_scope_node_init(const pm_node_t *node, pm_scope_node_t *scope, pm_scope_node_t *previous, pm_parser_t *parser) {
     scope->base.type = PM_SCOPE_NODE;
     scope->base.location.start = node->location.start;
     scope->base.location.end = node->location.end;
 
-    scope->ast_node = node;
+    scope->previous = previous;
+    scope->parser = parser;
+    scope->ast_node = (pm_node_t *)node;
     scope->parameters = NULL;
     scope->body = NULL;
+    scope->constants = NULL;
+    if (previous) {
+        scope->constants = previous->constants;
+    }
+    scope->index_lookup_table = NULL;
+
     pm_constant_id_list_init(&scope->locals);
 
     switch (PM_NODE_TYPE(node)) {

prism/prism.h

@@ -34,7 +34,7 @@ void pm_print_node(pm_parser_t *parser, pm_node_t *node);
 void pm_parser_metadata(pm_parser_t *parser, const char *metadata);
 
 // Generate a scope node from the given node.
-void pm_scope_node_init(pm_node_t *node, pm_scope_node_t *dest);
+void pm_scope_node_init(const pm_node_t *node, pm_scope_node_t *scope, pm_scope_node_t *previous, pm_parser_t *parser);
 
 // The prism version and the serialization format.
 PRISM_EXPORTED_FUNCTION const char * pm_version(void);