LLVM updated to 174210

Updated to work with revision 174210 of LLVM, in which many of the
header files have been moved into include/llvm/IR/.
Code refactoring

Split instrument_entire_function() into a few, more manageable pieces:
instrument_load_store(), instrument_call(), and instrument_other().
More code refactoring

Split bytesflops.cpp into a set of smaller, more manageable files:
bytesflops.cpp, bytesflops.h, helpers.cpp, init.cpp, and
instrument.cpp.