createReachingDefinitions,assignValnums,pic16_destructDF,
pic16_createDF,pic16_vcg_dumpedges,pic16_vcg_dump_default):
prevent NULL pointer dereferences
* device/lib/pic/libdev/pic16f886.c,
* device/lib/pic/libdev/pic16f887.c: svn mv'ed to disabled_* to
prevent building them, gputils do not really support them yet