Roslyn should not shadow copy redirected razor assemblies #12307
Description
In VS, Razor redirects the compiler assemblies via an IAnalyzerRedirector mechanism. However, it doens't implement an IAnalyzerPathResolver which means that the assemblies are shadow copied.
That is not just an unnecessary perf penalty but can cause issues with ALC resolution.
We should implement a path resolver as well, so that our redirected assemblies are never shadow copied.