Description:
------------
PDO Driver fails when updating a blob field with a large string content.
Our test show SIGSEGV happens from about 92000 chars filled in blob parameter by $Statement->bindValue($Name, $Value);

Some facts:
- Error is raised in Execute, not in BindValue
- Records in database are updated


DB Field is declared as:

Firebird 2.5.5
BLOB SUB_TYPE 1 SEGMENT SIZE 100 CHARACTER SET UTF8 COLLATE UTF8

Script is striped down from our code. Always reproducible.

Test script:
---------------
<?php

$D = [
	'kind' => 'firebird',
	'host' => '10.10.10.IP',
	'port' => 3050,
	'base' => 'database',
	'charset' => 'utf8',
	'user' => 'SYSDBA',
	'password' => 'password here',
	'options' => []
];

$H = $D['kind'].':host='.$D['host'].';port='.$D['port'].';dbname='.$D['base'].';charset='.$D['charset'];

$C = new \PDO($H, $D['user'], $D['password'], $D['options']);

if (!$S = $C->prepare('update ta_table set description = :description where id = 370'))
	return false;

$S->bindValue('description', str_repeat('a', 100000));

if (!$S->execute())
		return false;

return true;

Actual result:
--------------
[05-Sep-2016 19:33:32] WARNING: [pool www] child 6612 exited on signal 11 (SIGSEGV) after 0.444558 seconds from start