[Kernel] XThread: Added mutex to set_name.

There is a small chance that game will spam requests for thread name change which will cause invalid free

src/xenia/kernel/xthread.cc

@@ -136,6 +136,7 @@ void XThread::set_last_error(uint32_t error_code) {
 }
 
 void XThread::set_name(const std::string_view name) {
+  std::lock_guard<std::mutex> lock(thread_lock_);
   thread_name_ = fmt::format("{} ({:08X})", name, handle());
 
   if (thread_) {

src/xenia/kernel/xthread.h

@@ -465,6 +465,8 @@ class XThread : public XObject, public cpu::Thread {
   bool running_ = false;
 
   int32_t priority_ = 0;
+
+  std::mutex thread_lock_;
 };
 
 class XHostThread : public XThread {