Refactor: Use generic Define bound kind

This commit consolidates `DefLocal` and `DefGlobal` into a single
`Define` bound kind. This simplifies the AST and makes it more
consistent.

It also introduces `DeclarationKind` to differentiate between variable
and parameter definitions.

src/ast/compiler/tco.rs

@@ -98,26 +98,19 @@ impl TCO {
                 addr: *addr,
                 value: Box::new(Self::transform(Rc::new((**value).clone()), false)),
             },
-            BoundKind::DefLocal {
+            BoundKind::Define {
                 name,
-                slot,
+                addr,
+                kind,
                 value,
                 captured_by,
-            } => BoundKind::DefLocal {
+            } => BoundKind::Define {
                 name: name.clone(),
-                slot: *slot,
+                addr: *addr,
+                kind: *kind,
                 value: Box::new(Self::transform(Rc::new((**value).clone()), false)),
                 captured_by: captured_by.clone(),
             },
-            BoundKind::DefGlobal {
-                name,
-                global_index,
-                value,
-            } => BoundKind::DefGlobal {
-                name: name.clone(),
-                global_index: *global_index,
-                value: Box::new(Self::transform(Rc::new((**value).clone()), false)),
-            },
             BoundKind::Destructure { pattern, value } => BoundKind::Destructure {
                 pattern: Box::new(Self::transform(Rc::new((**pattern).clone()), false)),
                 value: Box::new(Self::transform(Rc::new((**value).clone()), false)),
@@ -143,10 +136,6 @@ impl TCO {
                     elements: new_elements,
                 }
             }
-            BoundKind::Parameter { name, slot } => BoundKind::Parameter {
-                name: name.clone(),
-                slot: *slot,
-            },
             BoundKind::Constant(v) => BoundKind::Constant(v.clone()),
             BoundKind::Get { addr, name } => BoundKind::Get {
                 addr: *addr,