This was GetAddressClass' behavior before. This is required when
debugging binaries that don't have mapping symbols ($a, $t, etc). These
binaries will only have the lower bit of the address set in the symbol
You should populate the m_address_class_map in ObjectFileELF::ParseSymbols() as this is where the m_address_class_map is already being populated. For ARM symbols, just check the flags and add an appropriate entry. Then this code doesn't need to exist here, but be moved into ObjectFileELF::ParseSymbols().
The function you are looking for is already implemented here (in the way Greg suggested). If it isn't working in your case then you should try to figure out why it isn't working in the way it is intended.