New comment by ericonr on void-packages repository

https://github.com/void-linux/void-packages/pull/27646#issuecomment-753674759

Comment:
```
/builddir/fceux-fceux-2.3.0/src/drivers/Qt/HexEditor.cpp:2171:11: error: expected id-expression before '(' token
 2171 |    if ( ::isascii( key ) )
```

C standard allows `isascii`  (or any functions from ctype.h) to be a macro as well as a function, so using the name here is wrong. Easiest solution is adding `#undef isascii` to the top of the file, best solution is not including `ctype.h` at all (if possible).