Fix ArrayObject::exchangeArray() return type

This method cannot return null.

Author: nikic

ext/spl/spl_array.c

@@ -1292,7 +1292,7 @@ PHP_METHOD(ArrayObject, exchangeArray)
 
 	if (intern->nApplyCount > 0) {
 		zend_throw_error(NULL, "Modification of ArrayObject during sorting is prohibited");
-		return;
+		RETURN_THROWS();
 	}
 
 	RETVAL_ARR(zend_array_dup(spl_array_get_hash_table(intern)));

ext/spl/spl_array.stub.php

@@ -78,7 +78,7 @@ public function __unserialize(array $data) {}
     /** @return Iterator */
     public function getIterator() {}
 
-    /** @return array|null */
+    /** @return array */
     public function exchangeArray(array|object $array) {}
 
     /** @return void */

ext/spl/spl_array_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: da85db1e5e985ddbefaf38598133e3cba46475f2 */
+ * Stub hash: a4bc5ec5a95aae6bfa53988316cfa396f4f9fb92 */
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_ArrayObject___construct, 0, 0, 0)
 	ZEND_ARG_TYPE_MASK(0, array, MAY_BE_ARRAY|MAY_BE_OBJECT, "[]")