re-pin to latest fixes, added small test for CreateJunction

src/ps_test/test_FileSystemProvider.cs

@@ -0,0 +1,16 @@
+using Xunit;
+using System;
+using System.Management.Automation;
+using Microsoft.PowerShell.Commands;
+
+namespace PSTests
+{
+    public static class FileSystemProviderTests
+    {
+        [Fact]
+        public static void TestCreateJunctionFails()
+        {
+            Assert.False(InternalSymbolicLinkLinkCodeMethods.CreateJunction("",""));
+        }
+    }
+}