Use all MSBuild binding redirects in NuGet.Frameworks AppDomain

[ladipro]

Context

The secondary AppDomain hosting NuGet.Frameworks was set up with a binding redirect for Microsoft.Build but not its dependencies. Additionally, MSBuild.exe loader policy was set to MultiDomainHost, making it possible to share only Framework assemblies between AppDomains, but still loading MSBuild assemblies domain specific. These issues were resulting in NGEN rejections at run-time.

Changes Made

Made the GenerateAppDomainConfig target use all binding redirects from MSBuild.exe.config and switched to MultiDomain loader policy. Also pluralized the relevant identifiers (redirect -> redirects).

Testing

Experimental VS insertion with PerfDDRITs & Speedometer runs.

[JanKrivanek]

Btw. the original change was not inserted into 17.9 - correct? (just trying to see if this will need backporting)

[ladipro]

Btw. the original change was not inserted into 17.9 - correct? (just trying to see if this will need backporting)

Correct, the regression is only in 17.10/main.

[JanKrivanek]

Looks good.
Though to me it is very advanced feature taking nontrivial efforts to understand - it definitely deserves more hints - I'd at least put the https://github.com/dotnet/msbuild/blob/main/documentation/NETFramework-NGEN.md#nugetframeworks in the comment of GenerateAppDomainConfig

[rainersigwald]

My instinct is to go forward with this and keep an eye out for other regressions. I agree that given where we are in the 17.10 cycle we have time to react if we do notice any (that overpower the gain in JIT).