Windows debug builds fail

[timwoj]

While building with -DCMAKE_BUILD_TYPE=Debug:

"C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\ALL_BUILD.vcxproj" (default target) (1) ->
"C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj" (default target) (3) ->
(ClCompile target) ->
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kevent.c(387,13): error C2186: '<': an operand cannot hav
e type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kevent.c(406,9): error C2186: '<': an operand cannot have
 type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kevent.c(504,5): error C2186: '<': an operand cannot have
 type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kqueue.c(314,5): error C2186: '<': an operand cannot have
 type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kqueue.c(382,9): error C2186: '<': an operand cannot have
 type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kqueue.c(400,9): error C2186: '<': an operand cannot have
 type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]
  C:\Users\timwo\Desktop\repos\libkqueue\src\common\kqueue.c(405,5): error C2186: '<': an operand cannot have
 type 'void' [C:\Users\timwo\Desktop\repos\libkqueue\build_x64_debug\objlib.vcxproj]

Release builds are fine, as covered by the GH workflow. A bisect says that e02fab6 is the first bad commit.

[timwoj]

Looking at the commit I linked to in the description, it probably won't work on Windows. pthread_mutex_unlock is redefined to be LeaveCriticalSection. That function returns VOID on Windows. unlikely gets redef'd away when not using __GNUC__, so it ends up trying to compare VOID < 0, which results in the error.