Ethel Morgan 5a0aa7824f Saturate exit codes to 255 for all builtins
After commit 6dd6a57c606afa6673f7950364f8a76610e4106d, 3 remaining
builtins were affected by uint8_t overflow: `exit`, `return`, and
`functions --query`.

This commit:
- Moves the overflow check from `builtin_set_query` to `builtin_run`.
- Removes a conflicting int -> uint8_t conversion in `builtin_return`.
- Adds tests for the 3 remaining affected builtins.
- Simplifies the wording for the documentation for `set --query`.
- Does not change documentation for `functions --query`, because it does
  not state the exit code in its API.
- Updates the CHANGELOG to reflect the change to all builtins.
2021-02-13 08:41:51 +01:00
..
2020-11-15 09:17:23 +01:00