Cleanup DotNetSdk

Uninstall-DotNetSdk .ps1

# Discussion at https://github.com/dotnet/sdk/issues/2295

function Uninstall-DotNetSdk {
  param (
    [parameter(Mandatory = $False)] [switch] $All,
    [parameter(Mandatory = $False)] [switch] $WhatIf
  )
  pushd $env:SystemRoot\System32
  Get-ChildItem HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall |
    Get-ItemProperty |
    Where-Object DisplayName -match "^Microsoft .NET Core SDK" |
    Where-Object BundleVersion -match "^\d+\.\d+\.\d+\d\d\.\d+$" |
    Group-Object { ([regex] "^(\d+\.\d+\.\d+)\d\d\.\d+$").Match($_.BundleVersion).Groups[1].Value } |
    Sort-Object { [regex]::Replace($_.Name, '\d+', { param($match) $match[0].Value.PadLeft(10,'0') }) } |
    ForEach-Object {
      $_.Group |
        Sort-Object {
          $versionMatch = ([regex] "^\d+\.\d+\.\d+(\d\d)\.(\d+)$").Match($_.BundleVersion)
          $v1 = $versionMatch.Groups[1].Value
          $v2 = $(if ($versionMatch.Groups[2].Value -eq "0") { "9".PadLeft(10,'9') } else { $versionMatch.Groups[2].Value.PadLeft(10,'0') })
          "$v1.$v2"
        } |
        Select-Object -SkipLast $(if ($All) { 0 } else { 1 }) |
        ForEach-Object {
          if ($_.QuietUninstallString -imatch '^"?([^"]+)"? +(/uninstall.*)$') {
            $file = $Matches[1]
            $arglist = $Matches[2]
            "Uninstall command: `"$file`" $arglist"
            if (-not $WhatIf) { Start-Process -FilePath $file -ArgumentList $arglist -Wait }
          }
        }
    }
  popd
}