feat(parser): 添加对嵌套 list() 解构赋值的支持

- 在 AssignOpTrait 中实现嵌套列表解构逻辑
- 添加临时变量生成用于处理嵌套数组
- 集成 parseAssignToList 方法处理嵌套 list 结构
- 保持原有非嵌套情况下的行为不变
- 添加完整的嵌套 list 解构功能测试用例
- 确保多层嵌套的列表解构能够正确执行

src/Php/Parser/AssignOpTrait.php

@@ -109,14 +109,21 @@ trait AssignOpTrait
                 continue;
             }
             if ($item instanceof ArrayItem) {
-                $oriInAssignExpr = $this->context->inAssignExpr;
-                $this->context->inAssignExpr = true;
-                $var = $this->parseIdentifier($item->value);
-                $this->context->inAssignExpr = $oriInAssignExpr;
-                if ($this->isVarExpr($item->value) and !$this->hasVar($var)) {
-                    $this->addLocalVar($var, self::TYPE_VAR);
+                if ($item->value instanceof Expr\List_) {
+                    $nestedTmp = $this->genTmpVarName();
+                    $this->addLocalVar($nestedTmp, self::TYPE_ARRAY);
+                    $code .= "{$nestedTmp} = {$tmpVar}.item({$k}); ";
+                    $code .= $this->parseAssignToList($item->value, new Variable($nestedTmp));
+                } else {
+                    $oriInAssignExpr = $this->context->inAssignExpr;
+                    $this->context->inAssignExpr = true;
+                    $var = $this->parseIdentifier($item->value);
+                    $this->context->inAssignExpr = $oriInAssignExpr;
+                    if ($this->isVarExpr($item->value) and !$this->hasVar($var)) {
+                        $this->addLocalVar($var, self::TYPE_VAR);
+                    }
+                    $code .= "{$var} = {$tmpVar}.item({$k}); ";
                 }
-                $code .= "{$var} = {$tmpVar}.item({$k}); ";
             } else {
                 abort($item);
             }

tests/aot/arrays/list-nested.phpt

@@ -0,0 +1,32 @@
+--TEST--
+nested list() destructuring
+--FILE--
+<?php
+function main(): void {
+    $arr = [1, [2, 3], 4];
+    list($a, list($b, $c), $d) = $arr;
+    echo $a, PHP_EOL;
+    echo $b, PHP_EOL;
+    echo $c, PHP_EOL;
+    echo $d, PHP_EOL;
+
+    // deeper nesting
+    $arr2 = [10, [20, [30, 40]], 50];
+    list($x, list($y, list($z, $w)), $v) = $arr2;
+    echo $x, PHP_EOL;
+    echo $y, PHP_EOL;
+    echo $z, PHP_EOL;
+    echo $w, PHP_EOL;
+    echo $v, PHP_EOL;
+}
+?>
+--EXPECT--
+1
+2
+3
+4
+10
+20
+30
+40
+50