Fix VS issue with unhandled exception on secondary threads (#103425)

* Fix VS issue with unhandled exception on secondary threads

When "just my code" is disabled, unhandled exceptions on secondary
threads cause the VS to stop without any stack trace shown. This is
similar to the recently fixed problem that was happening with user
unhandled exception treatment.
The exception is rethrown as native exception after leaving the last
managed frame and it propagates to the `ManagedThreadBase_DispatchOuter`
where it is caught. The debugger gets notified from there, but all of
the managed stack frames are gone at that point, so the debugger cannot
show them.
The fix is to report exception on a secondary thread as unhandled
earlier, right in the SfiNext where we report it for the primary
threads. The secondary thread is different in having the
DebuggerU2MCatchHandlerFrame on stack while in the primary thread case,
there is no explicit frame.

Close #103385

* Modify the check for DebuggerU2MCatchHandlerFrame

We need to check that it is also the topmost frame

---------

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

src/coreclr/vm/exceptionhandling.cpp

@@ -8213,6 +8213,11 @@ void FailFastIfCorruptingStateException(ExInfo *pExInfo)
     }
 }
 
+static bool IsTopmostDebuggerU2MCatchHandlerFrame(Frame *pFrame)
+{
+    return (pFrame->GetVTablePtr() == DebuggerU2MCatchHandlerFrame::GetMethodFrameVPtr()) && (pFrame->PtrNextFrame() == FRAME_TOP);
+}
+
 static void NotifyExceptionPassStarted(StackFrameIterator *pThis, Thread *pThread, ExInfo *pExInfo)
 {
     if (pExInfo->m_passNumber == 1)
@@ -8289,7 +8294,7 @@ static void NotifyExceptionPassStarted(StackFrameIterator *pThis, Thread *pThrea
                     pFrame = pFrame->PtrNextFrame();
                     _ASSERTE(pFrame != FRAME_TOP);
                 }
-                if ((pFrame->GetVTablePtr() == FuncEvalFrame::GetMethodFrameVPtr()) || (pFrame->GetVTablePtr() == DebuggerU2MCatchHandlerFrame::GetMethodFrameVPtr()))
+                if ((pFrame->GetVTablePtr() == FuncEvalFrame::GetMethodFrameVPtr()) || IsTopmostDebuggerU2MCatchHandlerFrame(pFrame))
                 {
                     EEToDebuggerExceptionInterfaceWrapper::NotifyOfCHFFilter((EXCEPTION_POINTERS *)&pExInfo->m_ptrs, pFrame);
                 }
@@ -8518,9 +8523,6 @@ extern "C" bool QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollideCla
         }
         else
         {
-            // TODO-NewEH: Currently there is one case of internal VM->managed transitions: COMToCLRDispatchHelperWithStack
-            // Either add handling here as well or rewrite it in C#, so that CallDescrWorker is the only path that
-            // needs to be handled here.
             size_t CallDescrWorkerInternalReturnAddress = (size_t)CallDescrWorkerInternal + CallDescrWorkerInternalReturnAddressOffset;
             if (GetIP(pThis->m_crawl.GetRegisterSet()->pCallerContext) == CallDescrWorkerInternalReturnAddress)
             {
@@ -8544,7 +8546,9 @@ extern "C" bool QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollideCla
             _ASSERTE(retVal != SWA_FAILED);
             _ASSERTE(pThis->GetFrameState() != StackFrameIterator::SFITER_SKIPPED_FRAME_FUNCTION);
 
-            if (pThis->m_crawl.GetFrame() == FRAME_TOP)
+            pFrame = pThis->m_crawl.GetFrame();
+            // Check if there are any further managed frames on the stack, if not, the exception is unhandled.
+            if ((pFrame == FRAME_TOP) || IsTopmostDebuggerU2MCatchHandlerFrame(pFrame))
             {
                 if (pTopExInfo->m_passNumber == 1)
                 {