[Bug-apl] ⎕FIO

[Juergen Sauermann]

Hello,

due to the problems with building DLLs under Windows, I have converted the
native function FILE_IO of GNU APL into  a new system function ⎕FIO.

⎕FIO is used exactly like FILE_IO, except that it cannot (and does not have to) be ⎕SVO'ed
beforehand.

The old FILE_IO native function is still present (and will be for a while) for backward compatibility.
The FILE_IO code has been  moved to ⎕FIO code, and FILE_IO is now merely a wrapper to the ⎕FIO code.
As a consequence, files opened with ⎕FIO are visible by FILE_IO and vice versa. A subtle difference between
⎕FIO and FILE_IO is that )CLEAR and friends close all files opened by ⎕FIO or FILE_IO.

The wslib5/FILE_IO.apl workspace has been updated to use ⎕FIO. If you use to )COPY that  workspace
instead of using FILE_IO directly, then everything remains as is.

/// Jürgen