stringUtils.ts: replace backslashes with forward-slashes only on non-Windows platforms.

Author: fgiancane8

src/extension/common/stringUtils.ts

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+import { getOSType, OSType } from './platform';
+
 /**
  * Replaces all instances of a substring with a new substring.
  */
@@ -61,5 +63,9 @@ export function fileToCommandArgumentForPythonExt(source: string): string {
 
     let result = toCommandArgumentForPythonExt(source);
 
-    return result.replace(/\\/g, '/');
+    if (getOSType() !== OSType.Windows) {
+        result = result.replace(/\\/g, '/');
+    }
+
+    return result;
 }