Possible leak in dvmAllocRegion

In error case mmapped ptr 'base' is not munmapped.

Change-Id: I9e43841371fee6b7c092fe9a8922ae82e78805ed
Fix handling of annotations whose classes are missing at runtime.

Bug: http://code.google.com/p/android/issues/detail?id=39854
Change-Id: I3089b693ff3084b093f991f991ac9273dea7356d