Fix the dot-sourcing behavior of pwsh -file for advanced-function scripts (PowerShell#27727)

Author: daxian-dbw

src/System.Management.Automation/engine/CommandProcessor.cs

@@ -778,7 +778,9 @@ private void Init(IScriptCommandInfo scriptCommandInfo)
             InitCommon();
 
             // If the script has been dotted, throw an error if it's from a different language mode.
-            if (!this.UseLocalScope)
+            // Unless it was a script loaded through -File, in which case the danger of dotting other
+            // language modes (getting internal functions in the user's state) isn't a danger.
+            if (!this.UseLocalScope && !scriptCmdlet.ShouldRethrowExitException)
             {
                 ValidateCompatibleLanguageMode(scriptCommandInfo.ScriptBlock, _context, Command.MyInvocation);
             }

src/System.Management.Automation/engine/runtime/CompiledScriptBlock.cs

@@ -2191,6 +2191,8 @@ internal sealed class PSScriptCmdlet : PSCmdlet, IDynamicParameters, IDisposable
         private bool _exitWasCalled;
         private bool _anyClauseExecuted;
 
+        internal bool ShouldRethrowExitException => _rethrowExitException;
+
         public PSScriptCmdlet(ScriptBlock scriptBlock, bool useNewScope, bool fromScriptFile, ExecutionContext context)
         {
             _scriptBlock = scriptBlock;