Add several classes from dx tool to the dexgen project

Dexgen depends on many classes from dx tool but for now there is no target
build of dx. That is why some of its classes need to be moved directly into
dexgen source code, as building target version of the whole dx project
is not an option. This CL produces a lot of duplicate classes in
dalvik/dx and dalvik/dexgen, but this will be resolved in future by removing
these classes from dalvik/dx.

Change-Id: I5411f92761d73c3ab555feaa345e5d150aa280ef
212 files changed