Built using csc 2.1.0.

Use the following steps (we're using 4.7.1 as example):

1. Copy existing v4.7/Makefile and src/v4.7/* to new folders and commit
2. Update PROFILE variable in v4.7.1/Makefile
3. Wire up new profile in Makefile in repo root
4. Run the generation script ./generate-refasm-sources.sh v4.7.1 some/path/to/netfx/referenceassemblies
5. Revert deletion of *.extra.cs
6. Revert changes that remove #if / #endif
7. Revert suspicious changes to:
   • Accessibility.cs (bug in GenApi)
   • Microsoft.VisualBasic.cs (bug in GenApi and wrong AssemblyCopyright/Product attribute)
   • Microsoft.VisualC.cs (bug in GenApi)
   • System.Data.Linq.cs (bug in GenApi)
   • System.Deployment.cs (we only have stub assemblies)
   • System.Runtime.DurableInstancing.cs (bug in GenApi)
   • System.Security.cs (bug in GenApi)
   • System.Web.Mobile.cs (we only have stub assemblies)
   • System.Workflow.*.cs (we only have stub assemblies)
8. Add new assemblies/facades to v4.7.1/Makefile
9. Run make -C v4.7.1 and ensure everything compiles