Add a script for generating a .sln containing all library projects (#186)

* Add a script for generating a .sln containing all library projects

* Add a script for generating a .sln containing all library projects

src/libraries/GenerateLibrariesSln.ps1

+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the MIT license.
+# See the LICENSE file in the project root for more information.
+
+# Creates a .sln that includes all of the library src, ref, or tests projects.
+
+param (
+    [string]$type = "src" # can also be "ref" or "tests"
+)
+
+if (($type -ne "src") -and
+    ($type -ne "ref") -and
+    ($type -ne "tests"))
+{
+    Write-Host "Unsupported type '$($type)'. Must be 'src', 'ref', or 'tests'."
+    exit
+}
+
+$SolutionName = "Libraries.$($type).Generated.sln"
+
+# Delete the existing solution if it exists
+if (Test-Path $SolutionName)
+{
+    Remove-Item $SolutionName
+}
+
+# Create the new solution
+dotnet new sln --name $([System.IO.Path]::GetFileNameWithoutExtension($SolutionName))
+
+# Populate it with all *\$type\*.csproj projects
+foreach ($f in Get-ChildItem -Recurse -Path $([System.IO.Path]::Combine("*", $type)) -Filter *.csproj)
+{
+    dotnet sln $SolutionName add --in-root $f.FullName
+}
+
+if ($type -eq "src")
+{
+    # Also add CoreLib if this is for src projects
+    dotnet sln $SolutionName add --in-root $f.FullName $([System.IO.Path]::Combine("..", "coreclr", "src", "System.Private.CoreLib", "System.Private.CoreLib.csproj"))
+}