Objdir sizes

[Martin Husemann <martin%duskware.de@localhost>]

I just noticed that my $OBJDIRs are vastly different in size.
Two (IMO) interesting observations:

 - llvm dirs are *way* too huge when building with MKDEBUG=yes,
   we really need a way to switch off -g for those builds (which then
   also likely makes most architectures buildable again on 4G RAM machines)

 - evbarm64-el is about four times the size of most other object dirs -
   I have no idea what is wrong here.

Martin