Remove scope field from Ast

src/checker.hpp

@@ -410,7 +410,6 @@ gb_global AstPackage *config_pkg      = nullptr;
 TypeAndValue type_and_value_of_expr (Ast *expr);
 Type *       type_of_expr           (Ast *expr);
 Entity *     implicit_entity_of_node(Ast *clause);
-Scope *      scope_of_node          (Ast *node);
 DeclInfo *   decl_info_of_ident     (Ast *ident);
 DeclInfo *   decl_info_of_entity    (Entity * e);
 AstFile *    ast_file_of_filename   (CheckerInfo *i, String   filename);