Merge TracyThread.hpp to TracySystem.cpp.

Keeping threading functions inside a source file prevents poisoning by
including windows.h.

common/TracySystem.hpp

@@ -1,12 +1,15 @@
 #ifndef __TRACYSYSTEM_HPP__
 #define __TRACYSYSTEM_HPP__
 
+#include <stdint.h>
 #include <thread>
 
 namespace tracy
 {
 
+uint64_t GetThreadHandle();
 void SetThreadName( std::thread& thread, const char* name );
+const char* GetThreadName( uint64_t id );
 
 }