Fix incorrect inheritance of private trait methods (#14163)

The bug was introduced in c6b75f9

Author: dstogov

Zend/tests/gh14009_005.phpt

@@ -0,0 +1,38 @@
+--TEST--
+GH-14009: Traits inherit prototype
+--FILE--
+<?php
+
+trait T {
+    private function test($s) {
+        echo $s . " -> ". __CLASS__ . "::" . __METHOD__ . "\n";
+    }
+}
+
+class A {
+	use T;
+	public function foo() {
+		$this->test(__METHOD__);
+	}
+	public function bar() {
+		$this->test(__METHOD__);
+	}
+}
+
+class B extends A {
+    use T;
+	public function foo() {
+		$this->test(__METHOD__);
+	}
+}
+
+(new A)->foo();
+(new A)->bar();
+(new B)->foo();
+(new B)->bar();
+?>
+--EXPECT--
+A::foo -> A::T::test
+A::bar -> A::T::test
+B::foo -> B::T::test
+A::bar -> A::T::test

Zend/zend_inheritance.c

@@ -1936,7 +1936,8 @@ static void zend_add_trait_method(zend_class_entry *ce, zend_string *name, zend_
 		do_inheritance_check_on_method(
 			fn, fixup_trait_scope(fn, ce), existing_fn, fixup_trait_scope(existing_fn, ce),
 			ce, NULL,
-			ZEND_INHERITANCE_CHECK_PROTO | ZEND_INHERITANCE_CHECK_VISIBILITY | ZEND_INHERITANCE_SET_CHILD_PROTO);
+			ZEND_INHERITANCE_CHECK_PROTO | ZEND_INHERITANCE_CHECK_VISIBILITY |
+			ZEND_INHERITANCE_SET_CHILD_CHANGED| ZEND_INHERITANCE_SET_CHILD_PROTO);
 	}
 }
 /* }}} */