Fix NativeAOT unhandled exception stack trace

The recent change to add a new exception handling mechanism to coreclr
has broken stack traces on unhandled exceptions in nativeaot.

This change fixes it by reverting the part of the change that caused the
problem and that turned out to not to be needed for the new exception
handling either.

Close dotnet#91298

src/coreclr/nativeaot/Runtime.Base/src/System/Runtime/ExceptionHandling.cs

@@ -708,14 +708,14 @@ private static void DispatchEx(scoped ref StackFrameIterator frameIter, ref ExIn
             uint startIdx = MaxTryRegionIdx;
             for (; isValid; isValid = frameIter.Next(&startIdx, &unwoundReversePInvoke))
             {
-                prevControlPC = frameIter.ControlPC;
-                prevOriginalPC = frameIter.OriginalControlPC;
-
                 // For GC stackwalking, we'll happily walk across native code blocks, but for EH dispatch, we
                 // disallow dispatching exceptions across native code.
                 if (unwoundReversePInvoke)
                     break;
 
+                prevControlPC = frameIter.ControlPC;
+                prevOriginalPC = frameIter.OriginalControlPC;
+
                 DebugScanCallFrame(exInfo._passNumber, frameIter.ControlPC, frameIter.SP);
 
                 UpdateStackTrace(exceptionObj, exInfo._frameIter.FramePointer, (IntPtr)frameIter.OriginalControlPC, frameIter.SP, ref isFirstRethrowFrame, ref prevFramePtr, ref isFirstFrame, ref exInfo);