Download the stage0 dotnet tools from the beta feed for windows.

Set the correct channel so that the stage0 binaries are downloaded
correctly.

** This commit cannot be directly merged from the release branch to the
master branch **

scripts/obtain/install-tools.ps1

@@ -13,7 +13,7 @@ if (!(Test-Path $env:DOTNET_INSTALL_DIR))
 
 # Install a stage 0
 header "Installing dotnet stage 0"
-_ "$RepoRoot\scripts\obtain\install.ps1"
+_ "$RepoRoot\scripts\obtain\install.ps1" @("$env:Channel")
 
 # Put stage0 on the PATH
 $env:PATH = "$env:DOTNET_INSTALL_DIR\cli\bin;$env:PATH"

scripts/obtain/install.ps1

@@ -3,11 +3,13 @@
 # Licensed under the MIT license. See LICENSE file in the project root for full license information.
 #
 
+param([string]$Channel="dev")
+
+
 $ErrorActionPreference="Stop"
 $ProgressPreference="SilentlyContinue"
 
 $Feed="https://dotnetcli.blob.core.windows.net/dotnet"
-$Channel="dev"
 $DotNetFileName="dotnet-win-x64.latest.zip"
 $DotNetUrl="$Feed/$Channel/Binaries/Latest"