refactor(php): 优化变量赋值类型检查逻辑

- 移除数组类型重分配检查的特殊处理
- 添加全局翻译器变量用于测试环境
- 引入通用变量赋值表达式检查方法
- 改进错误消息中的变量名显示格式
- 统一变量类型转换错误处理流程

phpunit/bootstrap.php

@@ -5,13 +5,16 @@ use PhpAot\Php\CompilerTest;
 use PhpAot\Php\Exception\TestError;
 
 require __DIR__ . '/../bin/bootstrap.php';
+require __DIR__ . '/../src/gen_stub.php';
 
 class BaseTest extends TestCase
 {
     protected function exec(string $expected, string $file): void
     {
         try {
+            global $translator;
             $compiler = CompilerTest::create(ROOT_PATH);
+            $translator = $compiler;
             $testFile = __DIR__ . '/code/' . $file;
             $compiler->addFiles([$testFile]);
             $compiler->prepareFile($testFile);

src/Php/CompilerBase.php

@@ -1551,10 +1551,7 @@ class CompilerBase extends \PhpAot\Core\Translator
                         $this->fatalError($left, "Cannot re-assign typed object `\${$var}` from `{$leftClass}` to `{$rightClass}`");
                     }
                 } else {
-                    if ($this->getVarType($var) === self::TYPE_ARRAY) {
-                        $this->fatalError($left, "Cannot re-assign `\${$var}` from object to array");
-                    }
-                    // TODO 右值是一个类型对象，但左值是一个 var ，许可，但无法标记对象类型
+                    $this->checkVarAssignExpr($left, $this->getVarType($var), self::TYPE_OBJECT);
                 }
             } else {
                 if ($this->isFuncCallExpr($right) and $this->isNameExpr($right->name)) {
@@ -5448,7 +5445,11 @@ class CompilerBase extends \PhpAot\Core\Translator
         if ($this->isNativeType($toType) and $this->isNativeType($fromType)) {
             return true;
         }
-        $this->fatalError($left, "Cannot re-assign variable from `{$fromType}` to `{$toType}`");
+        $varName = 'variable';
+        if ($this->isVarExpr($left)) {
+            $varName = '`$' . $this->parseIdentifier($left) . '`';
+        }
+        $this->fatalError($left, "Cannot re-assign $varName from `{$fromType}` to `{$toType}`");
     }
 
     protected function mustNoCall(NodeAbstract $node): void