Test that "make corevm" works as expected

[dukeleto]

It seems that often a refactor causes "make corevm" to build more than it should (like PGE). We need a test to verify that it works correctly, so this is caught early.

From #parrot on 6. March 2010:

19:28:26 <@dukeleto> we *reaaaaaaally* need a test that verifies that "make corevm" does what it is supposed to do
19:30:03 <@allison> dukeleto: difficult to test
19:31:36 <@dukeleto> allison: sure, but a worthy goal. the test would have to create a copy of the source tree and then verify that it is doing the right thing. not something 
                     that should be part of "make test", but I would say it would be good to have that in "make fulltest"
19:32:31 <@allison> duke: it could check a list of files that shouldn't exist after a "make realclean" and "make corevm"
19:32:37 <@dukeleto> every time "make corevm" breaks, you can hear a screeching halt of productivity from some devs that rely on it, like plobsing
19:32:42 <@dukeleto> allison: that is a nice idea