Refactor Destructure to handle assignments

Renames `DefDestructure` to `Destructure` to better reflect its use in
both definitions and assignments.
Introduces `bind_assign_pattern` to handle assignment destructuring in
the binder.
Adds `test_assign_destructuring` to verify assignment destructuring
functionality.

src/ast/compiler/bound_nodes.rs

@@ -82,8 +82,8 @@ pub enum BoundKind<T = ()> {
         value: Box<BoundNode<T>>,
     },
 
-    /// A destructuring definition (can be local or global depending on the pattern)
-    DefDestructure {
+    /// A destructuring operation (can be a definition or an assignment depending on the pattern)
+    Destructure {
         pattern: Box<BoundNode<T>>,
         value: Box<BoundNode<T>>,
     },
@@ -194,11 +194,11 @@ where
                 },
             ) => na == nb && ga == gb && va == vb,
             (
-                BoundKind::DefDestructure {
+                BoundKind::Destructure {
                     pattern: pa,
                     value: va,
                 },
-                BoundKind::DefDestructure {
+                BoundKind::Destructure {
                     pattern: pb,
                     value: vb,
                 },
@@ -265,7 +265,7 @@ impl<T> BoundKind<T> {
             BoundKind::DefGlobal {
                 name, global_index, ..
             } => format!("DEF_GLOBAL({}, Idx:{})", name.name, global_index),
-            BoundKind::DefDestructure { .. } => "DEF_DESTRUCTURE".to_string(),
+            BoundKind::Destructure { .. } => "DESTRUCTURE".to_string(),
             BoundKind::Lambda {
                 params, upvalues, ..
             } => {