__threading_support: Remove (void) in favor of ().

[brucem]

Summary

This fixes a clang-tidy warning when building something that uses
this file.

[mclow.lists]

Which clang-tidy module generates this warning, and what is the actual warning?

[brucem]

This is modernize-redundant-void-arg: https://clang.llvm.org/extra/clang-tidy/checks/modernize-redundant-void-arg.html

[brucem]

Can we revive this review? I'd still like to land it ...

[mclow.lists]

This looks fine to me.

libcxx/trunk/include/__threading_support

int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
                                __libcpp_timespec_t *__ts);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_condvar_destroy(__libcpp_condvar_t* __cv);
 
 // Execute once
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
-                          void (*init_routine)(void));
+                          void (*init_routine)());
 
 // Thread id
 _LIBCPP_THREAD_ABI_VISIBILITY
 bool __libcpp_thread_id_equal(__libcpp_thread_id t1, __libcpp_thread_id t2);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 bool __libcpp_thread_id_less(__libcpp_thread_id t1, __libcpp_thread_id t2);
 

 
 int __libcpp_condvar_destroy(__libcpp_condvar_t *__cv)
 {
   return pthread_cond_destroy(__cv);
 }
 
 // Execute once
 int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
-                          void (*init_routine)(void)) {
+                          void (*init_routine)()) {
   return pthread_once(flag, init_routine);
 }
 
 // Thread id
 // Returns non-zero if the thread ids are equal, otherwise 0
 bool __libcpp_thread_id_equal(__libcpp_thread_id t1, __libcpp_thread_id t2)
 {
   return pthread_equal(t1, t2) != 0;