Merge pull request #4153 from dotnet/AArnott-patch-1

Correct unobserved Task exception behavior doc

Author: AArnott

xml/System.Threading.Tasks/Task.xml

@@ -2599,7 +2599,7 @@ Task t Status: RanToCompletion, Result: 42
           <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- Tasks that throw unhandled exceptions store the resulting exception and propagate it wrapped in a <xref:System.AggregateException> in calls to <xref:System.Threading.Tasks.Task.Wait%2A> or in accesses to the <xref:System.Threading.Tasks.Task.Exception%2A> property. Any exceptions not observed by the time the task instance is garbage collected will be propagated on the finalizer thread. For more information and an example, see [Exception Handling (Task Parallel Library)](~/docs/standard/parallel-programming/exception-handling-task-parallel-library.md).  
+ Tasks that throw unhandled exceptions store the resulting exception and propagate it wrapped in a <xref:System.AggregateException> in calls to <xref:System.Threading.Tasks.Task.Wait%2A> or in accesses to the <xref:System.Threading.Tasks.Task.Exception%2A> property. On .NET Framework 4.0, any exceptions not observed by the time the task instance is garbage collected will be propagated on the finalizer thread, which crashes the process. On .NET Framework 4.5 and later the default behavior changed so unobserved exceptions are not rethrown from the Finalizer. .NET Core does not rethrow the exception on the Finalizer. For more information and an example, see [Exception Handling (Task Parallel Library)](~/docs/standard/parallel-programming/exception-handling-task-parallel-library.md).  
   
  ]]></format>
         </remarks>