Extract trivial extern type alias detection to module
diff --git a/gen/src/write.rs b/gen/src/write.rs
index 89e6ddd..bf60432 100644
--- a/gen/src/write.rs
+++ b/gen/src/write.rs
@@ -4,7 +4,7 @@
use crate::gen::{builtin, include, Opt};
use crate::syntax::atom::Atom::{self, *};
use crate::syntax::symbol::Symbol;
-use crate::syntax::types::TrivialReason;
+use crate::syntax::trivial::TrivialReason;
use crate::syntax::{
derive, mangle, Api, Enum, ExternFn, ExternType, Pair, RustName, Signature, Struct, Trait,
Type, Types, Var,