The alltrue/anytrue functions did not correctly handle unknown values.
This commit changes these functions so that the result is unknown if:
- The list argument is unknown
- For alltrue: any elements are unknown
- For anytrue: any elements are unknown and no known elements are true
The last change is a little subtle, so there are test cases to cover it
specifically. Examples:
- anytrue(unknown) -> unknown
- anytrue(false, unknown) -> unknown
- anytrue(false, unknown, true) -> true
df626e898c