mt_rand() behavior change is not in UPGRADING

Hi all,

It's nice to see mt_rand() behavior is improved.

[yohgaki@dev ~]$ php-5.6 -r "var_dump(mt_rand(222,
'99999999999999999999999'));"
int(115282844144104926)
[yohgaki@dev ~]$ php-7.0 -r "var_dump(mt_rand(222,
'99999999999999999999999'));"

Warning: mt_rand() expects parameter 2 to be integer, string given in
Command line code on line 1
NULL

However, returning NULL for invalid range may result in serious issues.
It's not documented in UPGRADING.

Could anyone responsible take care of it?
I suppose mt_srand() behavior has changed also.
There may be others.

This change is not mt_rand specific, it applies to all internal functions.
See https://wiki.php.net/rfc/zpp_fail_on_overflow. You are right that it is
not mentioned in UPGRADING yet.

Nikita