feat(compiler): 添加闭包表达式支持

- 在 CompilerBase.php 中添加对 Expr_Closure 节点类型的解析处理
- 实现 parseClosure 方法来编译 PHP 闭包为 C++ 代码
- 添加临时变量生成和缩进级别管理逻辑
- 处理闭包参数和 use 子句中的变量捕获
- 验证闭包中使用的变量是否已定义
- 添加闭包示例文件 closure.php 和对应测试文件
- 修复 fcall.php 中的调试输出注释问题

examples/closure.php

@@ -0,0 +1,14 @@
+<?php
+function main(): int
+{
+    $a = 100;
+    $b = [1, 2, 3];
+    $fn = function ($x) use ($a, $b)
+    {
+        var_dump($a);
+        var_dump($b);
+        var_dump($x);
+    };
+    $fn(1000);
+    return 0;
+}

examples/fcall.php

@@ -17,4 +17,7 @@ function main()
 {
     $o = new A;
     $o->foo(1, 2);
+    var_dump($xxx);
+//    var_dump($arr2['hello']);
+//    var_dump($o2->null);
 }

src/Php/CompilerBase.php

@@ -375,6 +375,8 @@ class CompilerBase extends \PhpAot\Core\Translator
                 return $this->parseThrow($expr);
             case 'Expr_ShellExec':
                 return $this->parseShellExec($expr);
+            case 'Expr_Closure':
+                return $this->parseClosure($expr);
             case 'Name_FullyQualified':
                 return $expr->name;
             case 'Scalar_Int':
@@ -3427,4 +3429,41 @@ class CompilerBase extends \PhpAot\Core\Translator
         }
         return $code;
     }
+
+    protected function parseClosure(Node\Expr\Closure $expr): string
+    {
+        $tmpVar = $this->genTmpVarName();
+
+        $fnCode = $this->getIndent() . 'php::ClosureFn ' . $tmpVar . ' = [](INTERNAL_FUNCTION_PARAMETERS, ' . self::TYPE_OBJECT . ' &this_, ' . self::TYPE_ARRAY . ' &vars_) {' . PHP_EOL;
+        $oriLocalVars = $this->localVars;
+        $this->localVars = [];
+        $this->indentLevel++;
+        foreach ($expr->params as $i => $param) {
+            $var = $this->parseIdentifier($param->var);
+            $fnCode .= 'auto ' . $var . ' = php::getCallArg(' . $i . ');' . PHP_EOL;
+            $this->addLocalVar($var, self::TYPE_VAR);
+        }
+        foreach ($expr->uses as $i => $useItem) {
+            $var = $this->parseIdentifier($useItem->var);
+            $fnCode .= 'auto ' . $var . ' = vars_.get(' . $i . ');' . PHP_EOL;
+            $this->addLocalVar($var, self::TYPE_VAR);
+        }
+        $fnCode .= $this->parseStmts($expr->stmts);
+        $this->indentLevel--;
+        $fnCode .= '};' . PHP_EOL;
+
+        $this->beforeStmtLines[] = $fnCode;
+        $this->localVars = $oriLocalVars;
+
+        $useVars = [];
+        foreach ($expr->uses as $useItem) {
+            $var = $this->parseIdentifier($useItem->var);
+            if ($this->isVarExpr($useItem->var) and !$this->hasVar($var)) {
+                $this->fatalError($expr, 'Variable `' . $var . '` is not defined');
+            }
+            $useVars [] = $var;
+        }
+
+        return 'php::newClosure(' . $tmpVar . ', { ' . implode(', ', $useVars) . ' })';
+    }
 }

tests/aot/closure-001.phpt

@@ -0,0 +1,28 @@
+--TEST--
+closure 001
+--FILE--
+<?php
+function main()
+{
+    $a = 100;
+    $b = [1, 2, 3];
+    $fn = function ($x) use ($a, $b) {
+        var_dump($a);
+        var_dump($b);
+        var_dump($x);
+    };
+    $fn(1000);
+}
+?>
+--EXPECT--
+int(100)
+array(3) {
+  [0]=>
+  int(1)
+  [1]=>
+  int(2)
+  [2]=>
+  int(3)
+}
+int(1000)
+