Reject dex files that attempt to use unspecified class access flags

Change-Id: Ib1ecf3dfe1856a9014c2e9b0d6a1725ba7617f98
Move verification of class access flags to libdex

Change-Id: I020a168cfff46e319b0bebb6c7477f0b4139c6de

Conflicts:
	libdex/DexSwapVerify.cpp
Remove dx/tests/120-disable-extend-ops

Support for the target-api flag was removed in 2011.

Change-Id: Id50c53f759d4e3a59f550dbeb6e733b68df58dd3