- When `as_json` returns `Infinity` or `NaN` as the value of any of the key,
  we don't used to call `as_json` on it as it was treated as primitive.
- This used to pass `Infinity` or `NaN` to `JSON.generate` and Ruby used
  to throw an error for `Infinity/NaN not allowed in JSON.`
- This patch changes the code to call `as_json` on these primitives so
  that they are converted to proper values before being passed to
  `JSON.generate`.
- Fixes #26877.