Bring back MainWindowTitle in PSHostProcessInfo (#11885)

* Bring back MainWindowTitle in PSHostProcessInfo

* Add test

src/System.Management.Automation/engine/remoting/commands/EnterPSHostProcessCommand.cs

@@ -765,7 +765,6 @@ namespace Microsoft.PowerShell.Commands
             private set;
         }
 
-#if !CORECLR
         /// <summary>
         /// Main window title of the process.
         /// </summary>
@@ -774,7 +773,6 @@ namespace Microsoft.PowerShell.Commands
             get;
             private set;
         }
-#endif
 
         #endregion
 
@@ -794,7 +792,6 @@ namespace Microsoft.PowerShell.Commands
 
             if (string.IsNullOrEmpty(appDomainName)) { throw new PSArgumentNullException("appDomainName"); }
 
-#if !CORECLR
             MainWindowTitle = string.Empty;
             try
             {
@@ -803,7 +800,6 @@ namespace Microsoft.PowerShell.Commands
             }
             catch (ArgumentException) { }
             catch (InvalidOperationException) { }
-#endif
 
             this.ProcessName = processName;
             this.ProcessId = processId;

test/powershell/Modules/Microsoft.PowerShell.Core/Get-PSHostProcessInfo.Tests.ps1

@@ -29,6 +29,11 @@ Describe "Get-PSHostProcessInfo tests" -Tag CI {
         (Get-PSHostProcessInfo).ProcessId | Should -Contain $PID
     }
 
+    It "Should return own self window title" {
+        $expected = (Get-Process -Id $PID).MainWindowTitle
+        (Get-PSHostProcessInfo -Id $PID).MainWindowTitle | Should -BeExactly $expected
+    }
+
     It "Should list info for other PowerShell hosted processes" {
         # Creation of the named pipe is async
         Wait-UntilTrue {