Fix a potential shutdown hang with Environment.Exit() on Windows de…

…pending on timing with GCs

- On Windows when a thread calls `ExitProcess`, the `TlsDestructionMonitor` for the thread appears to be destructed after all other threads in the process are torn down. It's possible for a GC to be in progress during that time, and the thread cleanup code in `TlsDestructionMonitor` tries to enter cooperative GC mode to fix the frame pointer, leading to a hang. Fixed by deactivating the `TlsDestructionMonitor` for the thread before calling `ExitProcess`.
- Also disabled the relevant test due to a different issue dotnet#83658 occurring in the same test on multiple platforms/architectures that is not understood yet.

Fixes dotnet#84006

src/coreclr/vm/ceemain.cpp

@@ -1727,6 +1727,11 @@ struct TlsDestructionMonitor
         m_activated = true;
     }
 
+    void Deactivate()
+    {
+        m_activated = false;
+    }
+
     ~TlsDestructionMonitor()
     {
         if (m_activated)
@@ -1768,6 +1773,11 @@ void EnsureTlsDestructionMonitor()
     tls_destructionMonitor.Activate();
 }
 
+void DeactivateTlsDestructionMonitor()
+{
+    tls_destructionMonitor.Deactivate();
+}
+
 #ifdef DEBUGGING_SUPPORTED
 //
 // InitializeDebugger initialized the Runtime-side COM+ Debugging Services

src/coreclr/vm/ceemain.h

@@ -46,6 +46,7 @@ void ForceEEShutdown(ShutdownCompleteAction sca = SCA_ExitProcessWhenShutdownCom
 void ThreadDetaching();
 
 void EnsureTlsDestructionMonitor();
+void DeactivateTlsDestructionMonitor();
 
 void SetLatchedExitCode (INT32 code);
 INT32 GetLatchedExitCode (void);

src/coreclr/vm/eepolicy.cpp

@@ -78,6 +78,13 @@ void SafeExitProcess(UINT exitCode, ShutdownCompleteAction sca = SCA_ExitProcess
         // disabled because if we fault in this code path we will trigger our Watson code
         CONTRACT_VIOLATION(ThrowsViolation);
 
+        // The TlsDestructionMonitor for this thread would likely be destructed at some point after ExitProcess is called. On
+        // Windows, this happens after all other threads in the process are torn down, and may occur while a GC is in progress.
+        // The thread cleanup code in TlsDestructionMonitor may try to enter cooperative GC mode to fix the frame pointer and
+        // wait for the pending GC to complete, leading to a hang. Since the process is being exited, deactivate the
+        // TlsDestructionMonitor for this thread before calling ExitProcess.
+        DeactivateTlsDestructionMonitor();
+
         ExitProcess(exitCode);
     }
 }

src/tests/issues.targets

@@ -30,6 +30,9 @@
         <ExcludeList Include="$(XunitTestBinBase)/baseservices/mono/runningmono/*">
             <Issue>This test is to verify we are running mono, and therefore only makes sense on mono.</Issue>
         </ExcludeList>
+        <ExcludeList Include="$(XunitTestBinBase)/baseservices/threading/regressions/2164/foreground-shutdown/*">
+            <Issue>https://github.com/dotnet/runtime/issues/83658</Issue>
+        </ExcludeList>
         <ExcludeList Include="$(XunitTestBinBase)/GC/Coverage/271010/**">
             <Issue>https://github.com/dotnet/runtime/issues/5933</Issue>
         </ExcludeList>
@@ -251,9 +254,6 @@
 
     <!-- Windows all architecture excludes -->
     <ItemGroup Condition="'$(XunitTestBinBase)' != '' and '$(TargetsWindows)' == 'true' and '$(RuntimeFlavor)' == 'coreclr'">
-        <ExcludeList Include="$(XunitTestBinBase)/baseservices/threading/regressions/2164/foreground-shutdown/*">
-            <Issue>https://github.com/dotnet/runtime/issues/84006</Issue>
-        </ExcludeList>
     </ItemGroup>
 
     <!-- Windows x64 specific excludes -->