Add jbevain/cecil (Mono.Cecil official repo) to source-build

[dagood]

Right now, we build mono/linker, which has a mono/cecil submodule. In 5.0, the mono/cecil submodule won't be used anymore, and instead the official Mono.Cecil package built by jbevain/cecil and published to the NuGet gallery will be adopted. This means we'll need to add this repository to avoid the prebuilt.

https://github.com/jbevain/cecil/

[omajid]

I am going to take a shot at it, but it will be slow as I am learning things.

[omajid]

Can't even figure out how to build it 😢

I filed jbevain/cecil#693 to get some help

[marek-safar]

There was a change in the strategy for .net5 and mono/cecil submodule is still used instead of Mono.Cecil NuGet.

[omajid]

Thanks, @marek-safar

@dagood Sounds like we should close this issue, then?

[dagood]

Thanks for the update. @marek-safar, do you know when dotnet/linker#1477 will end up in a release? rc2, GA?

That PR looks like it'll make our prebuilt disappear once that happens, which is good.

[marek-safar]

@dagood dotnet/linker#1477 should be included in rc2 but last time I checked the update was sitting in dotnet/sdk PRs queue