fir: Improve field order, fix checks

Author: CohenArthur

fir/src/checks.rs

@@ -118,7 +118,7 @@ impl<T: Debug> Fir<T> {
                     // FIXME: Check `to` as well
                 }
                 Kind::Assignment { to, from: _ } => {
-                    check!(to => Kind::TypedValue { .. }, node);
+                    check!(to => Kind::TypedValue { .. } | Kind::Binding { .. }, node);
                     // FIXME: Check `from` as well
                 }
                 Kind::Instantiation {

fir/src/lib.rs

@@ -254,9 +254,9 @@ impl<T> Index<&OriginIdx> for Fir<T> {
 
 #[derive(Debug, Clone)]
 pub struct Node<T = ()> {
-    pub data: T,
     pub origin: OriginIdx,
     pub kind: Kind,
+    pub data: T,
 }
 
 /// An instance of [`Fir`] is similar to a graph, containing [`Node`]s and relationships binding them together.