Description:
------------
Compiling a php file with a shebang causes no executable php file.

Reproduce code:
---------------
compile code:

$f = fopen('target.php', "w");
bcompiler_write_header($f);
bcompiler_write_file($f, 'source.php');
bcompiler_write_footer($f);
fclose($f);

file:
#!/usr/bin/php
<?php
echo 'Hello World' . "\n";
?>

Expected result:
----------------
$ ./target.php 
Hello World

Actual result:
--------------
$ ./target.php 
./target.php: Exec format error. Binary file not executable.
Exit 1

$ php target.php 
#!/usr/bin/php
Hello World