Description:
------------
The PDO::exec() does not handle the error if the first command is successfully completed.

Environment:
=====================================================================
PHP         : ~/php-install/bin/php 
PHP_SAPI    : cli
PHP_VERSION : 7.3.8-dev
ZEND_VERSION: 3.3.8-dev
PHP_OS      : Linux - Linux ... 4.18.0-21-generic #22~18.04.1-Ubuntu SMP Thu May 16 15:07:19 UTC 2019 x86_64
INI actual  : ~/php-install/lib/php.ini
More .INIs  :  

Test script:
---------------
    /** @var PDO $db */
    $res = $db->exec("INSERT INTO test(id, label) VALUES (41, 'x'); INSERT INTO test_bad(id, label) VALUES (42, 'y')");

    if( $res === false ){
        print 'OK';
    }
    else{
        var_dump($res);
        print 'Failed, because the command ran!';
    }

The full script is available here: https://github.com/szicsu/php-src/blob/PHP-7.3/ext/pdo_mysql/tests/pdo_mysql_exec_multi_command.phpt

The error message comes back from mysql but is not handled:
sendto(3, "_\0\0\0\3INSERT INTO test(id, label) VALUES (41, 'x'); INSERT INTO test_bad(id, label) VALUES (42, 'y')", 99, MSG_DONTWAIT, NULL, 0) = 99
poll([{fd=3, events=POLLIN|POLLERR|POLLHUP}], 1, 86400000) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\7\0\0\1\0\1\0\n\0\0\0", 32768, MSG_DONTWAIT, NULL, NULL) = 11
poll([{fd=3, events=POLLIN|POLLERR|POLLHUP}], 1, 86400000) = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "/\0\0\2\377z\4#42S02Table 'php_src.test_bad' doesn't exist", 32768, MSG_DONTWAIT, NULL, NULL) = 51