Description:
------------
Running this program results in invalid data.
May also causes PHP to crash.
Works fine without JIT.

The problem has been narrowed as best as I can.
The original problem was a PHP crash using JIT in a much larger application.

Fails the same in Apache 2.4 or CLI (both 64bits)

Test script:
---------------
<?php 
$a = null; // the problem only occurs when set to NULL
test($a, 'y');

function test($str, $pad) {
	$x = $str . str_repeat($pad, 15); // $x now contains "yyyyyyyyyyyyyyy"
	var_dump($x);
	echo '<br/>'; 
	
 	$gft = new gft();
	$gft->info(33);
	
	// $x has been changed ????
	// $x contains what was echoed in the function 'info'
	var_dump($x); 
	echo '<br/>'; 
} 
class gft{
	private $strVal = 'abcd ';	
	public function info($info, $prefix = ' Info:'){
		echo $this->strVal.$prefix.serialize($info).'aaaa';
		echo '<br/>'; 
	}
}


Expected result:
----------------
string(15) "yyyyyyyyyyyyyyy"
xxxx Info:i:33;aaaa
string(15) "yyyyyyyyyyyyyyy"

Actual result:
--------------
string(15) "yyyyyyyyyyyyyyy"
xxxx Info:i:33;aaaa
string(19) "xxxx Info:i:33;aaaa"