mie: add some convenience functions for func, block, and builder

mie/func.c

@@ -80,6 +80,26 @@ struct mie_value *mie_func_generate_value_name(
 	return b_unbox(struct mie_value, name, v_name);
 }
 
+struct mie_block *mie_func_get_first_block(struct mie_func *func)
+{
+	b_queue_entry *entry = b_queue_first(&func->f_blocks);
+	if (!entry) {
+		return NULL;
+	}
+
+	return (struct mie_block *)b_unbox(struct mie_value, entry, v_entry);
+}
+
+struct mie_block *mie_func_get_last_block(struct mie_func *func)
+{
+	b_queue_entry *entry = b_queue_last(&func->f_blocks);
+	if (!entry) {
+		return NULL;
+	}
+
+	return (struct mie_block *)b_unbox(struct mie_value, entry, v_entry);
+}
+
 static struct mie_type *get_type(struct mie_value *v)
 {
 	struct mie_func *f = MIE_FUNC(v);