Merge pull request microsoft#226976 from microsoft/tyriar/222237_3

Use OS separator when injecting ../ completion

Author: Tyriar

src/vs/workbench/contrib/terminal/browser/media/shellIntegration.ps1

@@ -388,9 +388,9 @@ function Send-Completions {
 			if ($completions.CompletionMatches.Count -gt 0 -and $completions.CompletionMatches.Where({ $_.ResultType -eq 3 -or $_.ResultType -eq 4 })) {
 				# Add `../ relative to the top completion
 				$firstCompletion = $completions.CompletionMatches[0]
-				if ($firstCompletion.CompletionText.StartsWith('../')) {
-					if ($completionPrefix -match '(\.\.\/)+') {
-						$parentDir = "$($matches[0])../"
+				if ($firstCompletion.CompletionText.StartsWith("..$([System.IO.Path]::DirectorySeparatorChar)")) {
+					if ($completionPrefix -match "(\.\.$([System.IO.Path]::DirectorySeparatorChar))+") {
+						$parentDir = "$($matches[0])..$([System.IO.Path]::DirectorySeparatorChar)"
 						$currentPath = Split-Path -Parent $firstCompletion.ToolTip
 						try {
 							$parentDirPath = Split-Path -Parent $currentPath