Promote warning to exception in ZipArchive::extractTo()

Closes GH-5516

Author: kocsismate

ext/zip/php_zip.c

@@ -2810,10 +2810,9 @@ static ZIPARCHIVE_METHOD(extractTo)
 					}
 				}
 				break;
-			case IS_LONG:
 			default:
-				php_error_docref(NULL, E_WARNING, "Invalid argument, expect string or array of strings");
-				break;
+				zend_argument_type_error(2, "must be of type array|string|null, %s given", zend_zval_type_name(zval_files));
+				RETURN_THROWS();
 		}
 	} else {
 		/* Extract all files */

ext/zip/php_zip.stub.php

@@ -137,7 +137,10 @@ public function unchangeIndex(int $index) {}
     /** @return bool */
     public function unchangeName(string $name) {}
 
-    /** @return bool */
+    /**
+     * @param array|string|null $files
+     * @return bool
+     */
     public function extractTo(string $pathto, $files = null) {}
 
     /** @return string|false */