pthread-win32 (<https://github.com/GerHobbelt/pthread-win32> commit
c66d2aa85adb31a38326ea90f5bb6f6410c348d3 (2024-10-18).
The following changes have been made:
 *  Warnings in `sched_getscheduler.c` and `sched_setscheduler.c` have been
    fixed.
 *  Modifications are marked by `/* OpenMPT */`.
 *  Obviously, unnecessary folders and files have been removed.
 *  For building, premake is used to generate Visual Studio project files.
    See ../build/premake/ for details.
