fix(php): 解决方法调用时的类型检查和反射问题

- 在方法调用前添加变量类型检查，防止对非对象类型调用方法
- 修复反射中获取方法返回类型的逻辑，改进变量命名避免冲突
- 添加对字符串类型参数调用对象方法的错误检测和提示

examples/error/call-str-method.php

@@ -0,0 +1,15 @@
+<?php
+function bar(): stdClass
+{
+    return new stdClass();
+}
+function foo(string $o)
+{
+    $o2 = bar();
+    $o2->call();
+}
+
+function main()
+{
+    foo("hello");
+}

src/Php/CompilerBase.php

@@ -4137,6 +4137,10 @@ class CompilerBase extends \PhpAot\Core\Translator
 
         // 可转为原生调用的 MethodCall
         if ($this->isVarExpr($expr->var) and $this->isNamedMethod($expr->name)) {
+            $type = $this->getVarType($object);
+            if (!$this->checkArgType($type, self::TYPE_OBJECT)) {
+                $this->fatalError($expr, 'Cannot call method `' . $expr->name->toString() . '()` on variable of type ' . $type);
+            }
             $this->context->beforeStmtLines[] = '// Method Call: ' . $object . '->' . $this->parseIdentifier($expr->name) . '()';
             try {
                 $nativeFunc = $this->findNativeMethod($expr, $object, $this->parseIdentifier($expr->name));

src/Php/Reflection.php

@@ -177,14 +177,14 @@ class Reflection
 
     public static function getMethodReturnType(string $class, string $method): ?string
     {
-        $class = self::getClass($class);
+        $classRef = self::getClass($class);
-        if (!$class) {
+        if (!$classRef) {
             return null;
         }
-        if (!$class->hasMethod($method)) {
+        if (!$classRef->hasMethod($method)) {
             return null;
         }
-        $method = $class->getMethod($method);
+        $methodDef = $classRef->getMethod($method);
-        return $method->getReturnType() ? $method->getReturnType()->getName() : null;
+        return $methodDef->getReturnType() ? $methodDef->getReturnType()->getName() : null;
     }
 }