Added example of using extract-bc to build a LLVM bitcode archive
Added example of using extract-bc to build a LLVM bitcode archive

SRI-CSL/whole-program-llvm,SRI-CSL/whole-program-llvm,travitch/whole-program-llvm,riyadparvez/whole-program-llvm,travitch/whole-program-llvm,BenjaminSchubert/whole-program-llvm,BenjaminSchubert/whole-program-llvm,travitch/whole-program-llvm,BenjaminSchubert/whole-program-llvm,BenjaminSchubert/whole-program-llvm,SRI-CSL/whole-program-llvm,SRI-CSL/whole-program-llvm,travitch/whole-program-llvm,SRI-CSL/whole-program-llvm,riyadparvez/whole-program-llvm,riyadparvez/whole-program-llvm,riyadparvez/whole-program-llvm