Added magic hashes for xxHash, non-cryptographic hash function

[spaze]

xxHash is an extremely fast non-cryptographic hash algorithm, working at RAM speed limit. It is proposed in four flavors (XXH32, XXH64, XXH3_64bits and XXH3_128bits). The latest variant, XXH3, offers improved performance across the board, especially on small data.

https://xxhash.com/

All four flavors are supported by PHP 8.1+.

Generated with a code like this, the numbers in the for loop had to be extended of course for the higher-bit flavors:

$algo = 'xxh32',
for ($i = 10_000_000; $i < 10_009_999; $i++) {
	$input = $i;
	$hash = hash($algo, $input);
	if ($hash == 0) {
		echo "$input:$hash\n";
	}
}
for ($i = 100_000_000; $i < 100_099_999; $i++) {
	$input = base64_encode($i);
	$hash = hash($algo, $input);
	if ($hash == 0) {
		echo "$input:$hash\n";
	}
}
for ($i = 100_000_000; $i < 100_099_999; $i++) {
	$input = base64_encode(random_bytes(9));
	$hash = hash($algo, $input);
	if ($hash == 0) {
		echo "$input:$hash\n";
	}
}