Send unlinkedClass back to hell, as requested.

The GC and Verify routines now can look inside classes better as well.

Basic ideas:
1) Pre-allocate the java.lang.Class class, and explicitly
set its clazz field to itself.

2) Put ClassObjects in status CLASS_IDX when their super and interface
array contain Dex indexes rather than object pointers. The GC
understands this, and uses that status to decide on marking those
fields or not.

Change-Id: Id84310b8a4ee27bf1b33e5b58ad9739fad659c4e
11 files changed