Add wrapper to prevent iteration of unordered maps
diff --git a/gen/build/src/cfg.rs b/gen/build/src/cfg.rs
index c15a173..6818bda 100644
--- a/gen/build/src/cfg.rs
+++ b/gen/build/src/cfg.rs
@@ -266,10 +266,10 @@
 #[cfg(not(doc))]
 mod r#impl {
     use crate::intern::{intern, InternedString};
+    use crate::syntax::map::UnorderedMap as Map;
     use crate::vec::{self, InternedVec as _};
     use lazy_static::lazy_static;
     use std::cell::RefCell;
-    use std::collections::HashMap;
     use std::fmt::{self, Debug};
     use std::marker::PhantomData;
     use std::ops::{Deref, DerefMut};
@@ -316,7 +316,7 @@
         //         cfg: AtomicPtr<super::Cfg>,
         //     }
         //
-        static CONST_DEREFS: RefCell<HashMap<Handle, Box<super::Cfg<'static>>>> = RefCell::default();
+        static CONST_DEREFS: RefCell<Map<Handle, Box<super::Cfg<'static>>>> = RefCell::default();
     }
 
     #[derive(Eq, PartialEq, Hash)]
diff --git a/gen/build/src/intern.rs b/gen/build/src/intern.rs
index 51bc07c..25b8706 100644
--- a/gen/build/src/intern.rs
+++ b/gen/build/src/intern.rs
@@ -1,5 +1,5 @@
+use crate::syntax::set::UnorderedSet as Set;
 use lazy_static::lazy_static;
-use std::collections::HashSet;
 use std::sync::{Mutex, PoisonError};
 
 #[derive(Copy, Clone, Default)]
@@ -13,7 +13,7 @@
 
 pub fn intern(s: &str) -> InternedString {
     lazy_static! {
-        static ref INTERN: Mutex<HashSet<&'static str>> = Mutex::new(HashSet::new());
+        static ref INTERN: Mutex<Set<&'static str>> = Mutex::new(Set::new());
     }
 
     let mut set = INTERN.lock().unwrap_or_else(PoisonError::into_inner);
diff --git a/gen/build/src/lib.rs b/gen/build/src/lib.rs
index f7d4182..204c89f 100644
--- a/gen/build/src/lib.rs
+++ b/gen/build/src/lib.rs
@@ -90,10 +90,10 @@
 use crate::gen::error::report;
 use crate::gen::Opt;
 use crate::paths::PathExt;
+use crate::syntax::map::{Entry, UnorderedMap};
 use crate::target::TargetDir;
 use cc::Build;
-use std::collections::btree_map::Entry;
-use std::collections::{BTreeMap, BTreeSet};
+use std::collections::BTreeSet;
 use std::env;
 use std::ffi::{OsStr, OsString};
 use std::io::{self, Write};
@@ -288,7 +288,7 @@
         });
     }
 
-    let mut header_dirs_index = BTreeMap::new();
+    let mut header_dirs_index = UnorderedMap::new();
     let mut used_header_links = BTreeSet::new();
     let mut used_header_prefixes = BTreeSet::new();
     for krate in deps::direct_dependencies() {
diff --git a/gen/src/nested.rs b/gen/src/nested.rs
index d94d36d..c030717 100644
--- a/gen/src/nested.rs
+++ b/gen/src/nested.rs
@@ -1,6 +1,6 @@
+use crate::syntax::map::UnorderedMap as Map;
 use crate::syntax::Api;
 use proc_macro2::Ident;
-use std::collections::HashMap as Map;
 
 pub struct NamespaceEntries<'a> {
     direct: Vec<&'a Api>,
diff --git a/gen/src/write.rs b/gen/src/write.rs
index 8242b2e..d2dbe02 100644
--- a/gen/src/write.rs
+++ b/gen/src/write.rs
@@ -3,6 +3,8 @@
 use crate::gen::out::OutFile;
 use crate::gen::{builtin, include, Opt};
 use crate::syntax::atom::Atom::{self, *};
+use crate::syntax::map::UnorderedMap as Map;
+use crate::syntax::set::UnorderedSet;
 use crate::syntax::symbol::Symbol;
 use crate::syntax::trivial::{self, TrivialReason};
 use crate::syntax::{
@@ -10,7 +12,6 @@
     Type, TypeAlias, Types, Var,
 };
 use proc_macro2::Ident;
-use std::collections::{HashMap, HashSet};
 
 pub(super) fn gen(apis: &[Api], types: &Types, opt: &Opt, header: bool) -> Vec<u8> {
     let mut out_file = OutFile::new(header, opt, types);
@@ -65,7 +66,7 @@
 }
 
 fn write_data_structures<'a>(out: &mut OutFile<'a>, apis: &'a [Api]) {
-    let mut methods_for_type = HashMap::new();
+    let mut methods_for_type = Map::new();
     for api in apis {
         if let Api::CxxFunction(efn) | Api::RustFunction(efn) = api {
             if let Some(receiver) = &efn.sig.receiver {
@@ -77,7 +78,7 @@
         }
     }
 
-    let mut structs_written = HashSet::new();
+    let mut structs_written = UnorderedSet::new();
     let mut toposorted_structs = out.types.toposorted_structs.iter();
     for api in apis {
         match api {