Ability to pick PHP value by reference in FFI.

Description

HI!
Currently the only way convert php value to FFI value is memcpy (or other ways with memory copying involved).
It could be wasting if we for example received large chunk from socket and need to deal with it through FFI.
For example,

/* Initial */
echo memory_get_usage(); // 348504

/* Got chunk of data */
$data = str_repeat('1', 512 << 10);
echo memory_get_usage(); // 876992

/* Defining the FFI type */
$type = FFI::arrayType(FFI::type('char'), [512 << 10]);
echo memory_get_usage(); // 877184

/* Allocating memory for type */
$ffiValue = FFI::new($type);
echo memory_get_usage(); // 1401984

/* And memcpy */
FFI::memcpy($ffiValue, $data, 512 << 10);
echo memory_get_usage(); 1402048

It would be great to have ability to reflect value from PHP to FFI using it by reference like so:

$data = str_repeat('1', 512 << 10);

/* @var FFI\CData $ffiValue */
$ffiValueCharArray = FFI::represent('char[]', &$data, size: 512 << 10); // No additional memory allocations for $data content

$ffiValueCharArray [1] = 5;
var_dump($data[1]); // $data changed by reference

$ffiValueInt32 = FFI::represent('int32_t', &$data, size: 4, offset: 12);
var_dump($ffiValueInt32->cdata); // substr($data, 12, 4) === "1111", we will get here 825307441

$ffiValueInt32->cdata = 10;
var_dump(bin2hex(substr($data, 12, 4))); // "0a000000"

Also could work not only with strings:

$int = 10;

$ffiValueInt64 = FFI::represent('int64_t', &$int); // length argument could be omitted if cast performed to fixed size type
var_dump($ffiValueInt64->cdata); // 10;

$ffiValueInt64->cdata = 20;
var_dump($int); // 20;

$readOverBoundary = FFI::represent('char[]', &$int, 10); // Exception: attempt to read over boundary

Commencez par les points d’entrée FFI::type, FFI::arrayType, FFI::new et FFI::memcpy présentés dans les exemples, puis déterminez si la sémantique de référence proposée correspond au modèle de valeurs et de mémoire de PHP. Le travail est terminé lorsqu’un design approuvé par les maintainers pour le comportement proposé de FFI::represent a été défini.