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, 2 insertions, 3 deletions

diff --git a/src/vm/clrex.cpp b/src/vm/clrex.cpp
index 6f8c157541..7c70bc98f1 100644
--- a/src/vm/clrex.cpp
+++ b/src/vm/clrex.cpp
@@ -343,9 +343,8 @@ HRESULT CLRException::SetErrorInfo()
 
         EX_TRY
         {
-            LeaveRuntimeHolderNoThrow lrh((size_t)::SetErrorInfo);                
-            ::SetErrorInfo(0, pErrorInfo);                                              
-            pErrorInfo->Release(); 
+            ::SetErrorInfo(0, pErrorInfo);
+            pErrorInfo->Release();
 
             // Success in setting the ErrorInfo on the thread
             hr = S_OK;