memprof: don't use thread user_id

memprof does not use user_id for anything,
so don't pass it to ThreadCreate.
Passing a random field of MemprofThread as user_id
does not make much sense anyway.

Depends on D113920.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D113921

compiler-rt/lib/memprof/memprof_thread.cpp

@@ -80,8 +80,7 @@ MemprofThread *MemprofThread::Create(thread_callback_t start_routine, void *arg,
   thread->start_routine_ = start_routine;
   thread->arg_ = arg;
   MemprofThreadContext::CreateThreadContextArgs args = {thread, stack};
-  memprofThreadRegistry().CreateThread(*reinterpret_cast<uptr *>(thread),
-                                       detached, parent_tid, &args);
+  memprofThreadRegistry().CreateThread(0, detached, parent_tid, &args);
 
   return thread;
 }