[scudo][NFC] Make tests runs with --gtest_repeat=2

compiler-rt/lib/scudo/standalone/tests/tsd_test.cpp

static void stressSharedRegistry(MockAllocator<SharedCaches> *Allocator) {
   {
     std::unique_lock<std::mutex> Lock(Mutex);
     Pointers.insert(Set.begin(), Set.end());
   }
 }
 
 TEST(ScudoTSDTest, TSDRegistryTSDsCount) {
   Ready = false;
+  Pointers.clear();
   using AllocatorT = MockAllocator<SharedCaches>;
   auto Deleter = [](AllocatorT *A) {
     A->unmapTestOnly();
     delete A;
   };
   std::unique_ptr<AllocatorT, decltype(Deleter)> Allocator(new AllocatorT,
                                                            Deleter);
   Allocator->reset();

compiler-rt/lib/scudo/standalone/tsd_exclusive.h

template <class Allocator> struct TSDRegistryExT {
 
   void initOnceMaybe(Allocator *Instance) {
     ScopedLock L(Mutex);
     if (LIKELY(Initialized))
       return;
     initLinkerInitialized(Instance); // Sets Initialized.
   }
 
-  void unmapTestOnly() {}
+  void unmapTestOnly() {
+    Allocator *Instance =
+        reinterpret_cast<Allocator *>(pthread_getspecific(PThreadKey));
+    if (!Instance)
+      return;
+    ThreadTSD.commitBack(Instance);
+    State = {};
+  }
 
   ALWAYS_INLINE void initThreadMaybe(Allocator *Instance, bool MinimalInit) {
     if (LIKELY(State.InitState != ThreadState::NotInitialized))
       return;
     initThread(Instance, MinimalInit);
   }
 
   ALWAYS_INLINE TSD<Allocator> *getTSDAndLock(bool *UnlockRequired) {