ref: add type/classname result for each gen_* function

src/compiler/generator/gen_reference.c

@@ -1,23 +1,24 @@
 #include <common/fzl_extern.h>
+#include <common/fzl_types.h>
 #include <compiler/fzl_token.h>
 #include <compiler/internals/gen.h>
 #include <stdbool.h>
 #include <stdio.h>
 
 // Type reference (convert T => T*)
-bool gen_reference(fzl_gen_t *gen, fzl_node_t *node)
+gen_res_t gen_reference(fzl_gen_t *gen, fzl_node_t *node)
 {
   if (!gen || !node)
-    return false;
+    return (gen_res_t){.error = true};
 
   char *refname = (char *)node->token->value;
   ssize_t slot  = gen_resolve_extern_type(gen, refname);
   if (slot == -1)
-    return false;
+    return (gen_res_t){.error = true};
 
   type_buf.kind = FZL_EXTERN_KIND_REF;
   type_buf.ref_target =
       (fzl_extern_type_ref_t){.is_primitive = false, .type_slot = slot};
 
-  return true;
+  return (gen_res_t){.error = false, .type = FZL_TYPE_NULL, .classname = NULL};
 }