Use Dispose() instead of Close() for CORECLR

src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/MshHostTraceListener.cs

@@ -68,6 +68,9 @@ namespace Microsoft.PowerShell.Commands
         [SecurityPermission(SecurityAction.LinkDemand)]
         protected override void Dispose(bool disposing)
         {
+#if CORECLR
+            base.Dispose(disposing);
+#else
             try
             {
                 if (disposing) 
@@ -79,8 +82,10 @@ namespace Microsoft.PowerShell.Commands
             {
                 base.Dispose(disposing);
             }
+#endif
         }                
 
+#if !CORECLR
         /// <summary>
         /// Closes the dialog and then calls the base class Close
         /// </summary>
@@ -91,6 +96,7 @@ namespace Microsoft.PowerShell.Commands
 
             base.Close();
         }
+#endif
 
         #endregion TraceListener constructors and disposer
 

src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/TraceExpressionCommand.cs

@@ -333,7 +333,7 @@ namespace Microsoft.PowerShell.Commands
                     foreach (FileStream fileStream in this.FileStreams)
                     {
                         fileStream.Flush();
-                        fileStream.Close();
+                        fileStream.Dispose();
                     }
                 }
                 GC.SuppressFinalize(this);

src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/TraceListenerCommandBase.cs

@@ -460,7 +460,7 @@ namespace Microsoft.PowerShell.Commands
                             true))
                     {
                         listenerToRemove.Flush();
-                        listenerToRemove.Close();
+                        listenerToRemove.Dispose();
                         source.Listeners.RemoveAt(index);
                     }
                 }
@@ -619,7 +619,7 @@ namespace Microsoft.PowerShell.Commands
                 foreach (TraceListener listener in pair.Value)
                 {
                     listener.Flush();
-                    listener.Close();
+                    listener.Dispose();
                 }
             }
             storedTraceSourceState.Clear ();