Allow MSBuild tests to access root of drive

[mruxmohan4]

Issue Description

Allow drive enumerating tests to access the root of a drive inside of Visual Studio. Currently, an UnauthorizedAccessException is thrown (so drive substitution is required for such tests to pass in VS).

Steps to Reproduce

Run subst z: <drive>:\<path> (or preferably, subst z: %TEMP%) on the command line for the below test to pass. This test can be added inside of CreateItem_Tests.cs.

       [Fact]
       public void WildcardDriveEnumerationTaskItemLogsWarning()
       {
           using (var env = TestEnvironment.Create())
           {
               ChangeWaves.ResetStateForTests();
               env.SetEnvironmentVariable("MSBUILDFAILONDRIVEENUMERATINGWILDCARD", "0");
               BuildEnvironmentHelper.ResetInstance_ForUnitTestsOnly();

               CreateItem t = new CreateItem();
               MockEngine engine = new MockEngine();

               t.BuildEngine = engine;
               t.Include = new ITaskItem[] { new TaskItem(@"z:\**\*.log") };
               bool succeeded = t.Execute();

               Assert.True(succeeded);
               Assert.Equal(1, engine.Warnings);
               engine.AssertLogContains("results in drive enumeration");

               ChangeWaves.ResetStateForTests();
           }
       }

Expected Behavior

The test case should pass and allow for drive enumeration to occur for MSBuild to properly log a warning when a drive enumerating wildcard is detected.

Actual Behavior

The test case throws an UnauthorizedAccessException and hangs.

Analysis

This occurs for attempts to log a warning in ProjectItem_Tests.cs and ProjectItemInstance_Tests.cs as well.

Versions & Configurations

Microsoft (R) Build Engine version 17.0.0+c9eb9dd64 for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.

17.0.0.52104