Issue: https://github.com/php/php-src/issues/10433
Author: tgeene
### Description
When using the function json_encode it will sometime lose all precision on floats being
used as values. It would be nice if a new constant was added that handled similar to
JSON_BIGINT_AS_STRING such as JSON_FLOAT_AS_STRING. I recommend this
solution as I don't know if simply maintain precision would be possible given the underlying
code of PHP.