feat(php): 支持常量别名解析和命名空间处理

- 实现 useAliases 映射来处理常量别名
- 添加命名空间类名解析逻辑到 getNamespacedClassName 方法
- 修复 parseUse 方法的参数类型声明为 Node\Stmt\Use_
- 更新变量命名提高代码可读性
- 添加 use-const.phpt 测试用例验证常量别名功能

src/Php/CompilerBase.php

@@ -3131,6 +3131,13 @@ class CompilerBase extends \PhpAot\Core\Translator
                 $fullName = $this->getNamespacedClassName($ns[0]);
                 $ce = $this->getClassEntryPtr($fullName);
                 return 'php::constant(' . $ce . ', ' . $this->getLiteralString($ns[1]) . ')';
+            } elseif (isset($this->useAliases[$name])) {
+                $name = $this->useAliases[$name];
+            } else {
+                $fullName = $this->getNamespacedClassName($name);
+                if ($fullName) {
+                    $name = $fullName;
+                }
             }
             return 'php::constant(nullptr, ' . $this->getLiteralString($name) . ')';
         }
@@ -4374,16 +4381,15 @@ class CompilerBase extends \PhpAot\Core\Translator
         }
     }
 
-    protected function parseUse(mixed $v2): string
+    protected function parseUse(Node\Stmt\Use_ $v2): string
     {
         $code = '';
         foreach ($v2->uses as $use) {
             $id = $this->parseIdentifier($use->name);
             if ($use->type === Node\Stmt\Use_::TYPE_FUNCTION) {
-                $rpos = strrpos($id, '\\');
+                $lastIndex = strrpos($id, '\\');
-                $fn = substr($id, $rpos + 1);
+                $fn = substr($id, $lastIndex + 1);
-                $ns = substr($id, 0, $rpos);
+                $ns = substr($id, 0, $lastIndex);
-                // fn => namespace
                 $this->useFunctions[$fn] = $ns;
             } else {
                 if ($id === 'native_types') {

tests/aot/use-const.phpt

@@ -0,0 +1,28 @@
+--TEST--
+aliasing imported constants to resolve naming conflicts
+--FILE--
+<?php
+
+namespace foo {
+    const baz = 42;
+}
+
+namespace bar {
+    const baz = 43;
+}
+
+namespace {
+    use const foo\baz;
+    use const bar\baz as bar_baz;
+    function main() {
+        var_dump(baz);
+        var_dump(bar_baz);
+        echo "Done\n";
+    }
+}
+
+?>
+--EXPECT--
+int(42)
+int(43)
+Done