Since C++17, the introduction of deduction guides for locking facilities
means that we no longer need to hardcode the mutex type into the locks
themselves, making it easier to switch mutex types, should it ever be
necessary in the future.
Many of these functions are carried over from Dolphin (where they aren't
used anymore). Given these have no use (and we really shouldn't be
screwing around with OS-specific thread scheduler handling from the
emulator, these can be removed.
The function for setting the thread name is left, however, since it can
have debugging utility usages.
While admirable as a means to ensure immutability, this has the
unfortunate downside of making the class non-movable. std::move cannot
actually perform a move operation if the provided operand has const data
members (std::move acts as an operation to "slide" resources out of an
object instance). Given Barrier contains move-only types such as
std::mutex, this can lead to confusing error messages if an object ever
contained a Barrier instance and said object was attempted to be moved.
This is also unused and superceded by standard functionality. The
standard library provides std::this_thread::sleep_for(), which provides
a much more flexible interface, as different time units can be used with
it.
This is an old function that's no longer necessary. C++11 introduced
proper threading support to the language and a thread ID can be
retrieved via std::this_thread::get_id() if it's ever needed.
