Update unavailable cmdlets

These cmdlets were made available in b9bf32d96.

docs/KNOWNISSUES.md

@@ -79,14 +79,11 @@ following cmdlets that exist in the FullCLR version:
 - ConvertFrom-String
 - ConvertTo-Html
 - Export-PSSession
-- Get-TraceSource
 - Import-PSSession
 - Invoke-RestMethod
 - Invoke-WebRequest
 - Out-GridView
 - Out-Printer
 - Send-MailMessage
-- Set-TraceSource
 - Show-Command
-- Trace-Command
 - Update-List