[php] Add extern for the `Attribute` class (#10270)

std/php/Attribute.hx

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C)2005-2021 Haxe Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package php;
+
+/**
+	@see https://www.php.net/manual/en/language.attributes.php
+**/
+@:native("Attribute")
+extern final class Attribute {
+	@:phpClassConst static final IS_REPEATABLE: Int;
+	@:phpClassConst static final TARGET_ALL: Int;
+	@:phpClassConst static final TARGET_CLASS_CONSTANT: Int;
+	@:phpClassConst static final TARGET_CLASS: Int;
+	@:phpClassConst static final TARGET_FUNCTION: Int;
+	@:phpClassConst static final TARGET_METHOD: Int;
+	@:phpClassConst static final TARGET_PARAMETER: Int;
+	@:phpClassConst static final TARGET_PROPERTY: Int;
+}