Remove hosting methods that always return false (#9930)

* Remove CLRIoCompletionHosted as it always returns false.
* Remove CLRSyncHosted as it always returns false.
* Remove CLRMemoryHosted as it always returns false.
* Remove CLRTaskHosted as it always returns false.
* Remove CLRAssemblyHosted, CLRGCHosted,and CLRSecurityHosted.
They are not called.
* Remove IsThreadPoolHosted as it always returns false.
* Remove EnterRuntime and LeaveRuntime, as they do nothing.
* Add back calls to RevertIfImpersonated and GCX_PREEMP.

I accidentally deleted the call to RevertIfImpersonated instead of just
removing an extra parameter.

When I removed the HR_LEAVE_RUNTIME_HOLDER macro from windowsruntime.h,
I not only removed a LeaveRuntimeHolder but also a GCX_PREEMP. So I added
it back. The holder and GCX_PREEMP where only inserted when the
FEATURE_LEAVE_RUNTIME_HOLDER macro was defined. Since it is always defined,
I removed it. Also as I understand it, you would always want to have a
GCX_PREEMP before calling into the Windows API as not to block the GC,
so I'm not sure why you would want to disable it.

1 files changed, 0 insertions, 9 deletions

diff --git a/src/vm/hosting.cpp b/src/vm/hosting.cpp
index 66f59ec183..620b9d6800 100644
--- a/src/vm/hosting.cpp
+++ b/src/vm/hosting.cpp
@@ -635,15 +635,6 @@ BOOL __DangerousSwitchToThread (DWORD dwSleepMSec, DWORD dwSwitchCount, BOOL goT
     }
     CONTRACTL_END;
 
-    if (CLRTaskHosted())
-    {
-        Thread *pThread = GetThread();
-        if (pThread && pThread->HasThreadState(Thread::TS_YieldRequested))
-        {
-            pThread->ResetThreadState(Thread::TS_YieldRequested);
-        }
-    }
-
     if (dwSleepMSec > 0)
     {
         // when called with goThroughOS make sure to not call into the host. This function