[asan][win] Fix ExitThread leak

Author: GkvJwa

compiler-rt/lib/asan/asan_win.cpp

@@ -143,9 +143,11 @@ static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {
 
   ThreadStartParams params;
   t->GetStartData(params);
+  // The ExitThread will end the current thread, causing destroy to be unable to
+  // be called.
+  t->Destroy();
 
   auto res = (*params.start_routine)(params.arg);
-  t->Destroy();  // POSIX calls this from TSD destructor.
   return res;
 }