[RFC] Permit trailing whitespace in numeric strings

Hej allihopa, Here's an RFC that's been lying in my drafts for uh… 26 months: https://wiki.php.net/rfc/trailing_whitespace_numerics I expect this should be an uncontroversial proposal, but maybe I'm jinxing it there. I hope you all like it. :) Thanks to Nikita for reminding me it existed and thus motivating me to pick it up again. Also thanks to Nikita for suggesting a potential follow-up RFC, and also making the “Saner string to number comparisons” RFC, both providing additional impetus for me to finally clean this up and put it to discussion. Thanks! Andrea