LONG_TELL Build issues WINDOWS

[ZRobison]

Hi,

I ran into an error when building with cmake using MinGW-W64 7.2.0 on windows.

It complains about `LONG_TELL' being defined in fileio.c.

There does not seem to be a LONG_TELL defined in the #elif defined(_WIN32) && !defined(__DJGPP__) macro branch.

I fixed this by just adding #define LONG_TELL ftello64 and it seemed to work

[terrelln]

@Cyan4973 you wrote LONG_SEEK for this branch 2 years ago in #542. Do you have the context to fix LONG_TELL on this branch?

It seems that we don't have a test for it on Appveyor.

[Cyan4973]

I don't remember to be fair.
But the fact that LONG_TELL is not defined for configuration defined(_WIN32) && !defined(__DJGPP__) can only be a bug.

I'm surprised it did not show up before.

[Cyan4973]

The code for defined(_WIN32) && !defined(__DJGPP__) was added by @ds77 two years ago.

Then 3 months ago, @kostmo added LONG_TELL to "fix --list on truncated files ".
The LONG_TELL macro was not added to defined(_WIN32) && !defined(__DJGPP__) configuration.
No one noticed, and it managed to pass all tests.

So it seems this configuration is not tested on Appveyor. Not sure if we can improve that.