Work to support typing compilation-unit level declarations in the shell.

Work to support typing compilation-unit level declarations in the shell.

There is a major problem with it though: Reflection keeps gettting data
confused if you are using any of the *Builder classes and ends up
referencing other classes.     This seems like a real bug in Emit, not
really just an intended side effect.

So until all of those issues are fixed, the code path is disabled, but
at least declaring types works now.

svn path=/trunk/mcs/; revision=111974