- Use the right path separator char for unix.
- Contruct some of the args to crossgen outside the loop.
- Add the null check inside Command.Environment.
- Use Crossgen's Ready To Run mode on all of the managed assemblies
that make up the shared framework.
- Upgrade the version of the shared framework to match what is used
in the rest of CLI (see the comment in SharedFrameworkTargets.cs to
understand why this is needed).
- Remove the IL mscorlib.dll image, since the Crossgen'd image is
already published.
Fixesdotnet/corefx#6753
