common/thread: Remove SleepCurrentThread()

This is also unused and superceded by standard functionality.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.

src/common/thread.cpp

@@ -25,13 +25,6 @@
 
 namespace Common {
 
-#ifdef _WIN32
-// Supporting functions
-void SleepCurrentThread(int ms) {
-    Sleep(ms);
-}
-#endif
-
 #ifdef _MSC_VER
 
 void SetThreadAffinity(std::thread::native_handle_type thread, u32 mask) {
@@ -97,10 +90,6 @@ void SetCurrentThreadAffinity(u32 mask) {
 }
 
 #ifndef _WIN32
-void SleepCurrentThread(int ms) {
-    usleep(1000 * ms);
-}
-
 void SwitchCurrentThread() {
     usleep(1000 * 1);
 }

src/common/thread.h

@@ -83,7 +83,6 @@ private:
     std::size_t generation; // Incremented once each time the barrier is used
 };
 
-void SleepCurrentThread(int ms);
 void SwitchCurrentThread(); // On Linux, this is equal to sleep 1ms
 void SetCurrentThreadName(const char* name);